Yogo sapphire
Encyclopedia
Yogo sapphires are a special cornflower blue
color variety of corundum
found only in Yogo Gulch, Judith Basin County, Montana
, United States. They are considered among the finest sapphire
s in the world, and by some gem experts, the finest. Sapphire mining at Yogo Gulch began in 1895, and the term "Yogo" is said to mean "blue sky" in the Piegan Blackfeet language. About $25 million of gemstone has been recovered by all mines at Yogo, and at least 28 million carat
s are estimated to still be in the ground.
The cornflower blue color of the Yogo is provided by trace amounts of iron
and titanium
. While sapphires were first discovered in Montana in 1865 it was not until 1895 that their quality and value was noticed and serious mining efforts began. Due to the unique nature of the dike that Yogo sapphires are found in, mining efforts at Yogo Gulch have been sporadic and rarely profitable. Yogo sapphires are rarer than diamonds. In 1969 the sapphire was designated the Montana state gemstone, along with Montana agate
.
Yogo Gulch is located in what today is Judith Basin County, Montana
, 12 miles (19.3 km) southwest (SW) of Utica, Montana and 45 miles (72.4 km) west-southwest (WSW) of Lewistown, Montana
. It lies east of Great Falls, Montana
. The area where Yogo sapphires are mined is a region historically inhabited by the Piegan Blackfeet people, and the word "Yogo" is alleged to mean "blue sky" in Piegan Blackfeet, although there is some dispute about this translation. At the time of discovery, this area was in southwestern Fergus County, Montana
. Yogo Gulch and Utica are now located in Judith Basin County, which was broken out from western Fergus County and eastern Cascade County, Montana
on December 10, 1920. Yogo Peak (el. 8625 feet (2,628.9 m)), Yogo Creek, Yogo Gulch, and the Yogo dike are located in the portion of the Little Belt Mountains
that lies within Judith Basin County. The Judith River
flows northeast out of the Little Belts towards Utica. East of the river is Pig-Eye Basin—where Jake Hoover, claimed to be the discoverer of Yogo sapphires, had a ranch. The Yogo area to the west. Yogo Peak is about 15 miles (24.1 km) west of the Judith River
. Yogo Creek originates there and flows southeast to its confluence with the Middle Fork of the Judith River a few miles upstream of where the Middle Fork joins the Judith. Yogo Gulch is located along the lower reaches of Yogo Creek, and the Yogo dike originates a few miles north of the stream's confluence, then runs from west-southwest to east-northeast from Yogo Creek to just before the Judith River.
Sapphires are a form of corundum
, which is crystalline aluminum oxide and its chemical formula is Al2O3. Corundum is the second hardest mineral (rating 9) on the Mohs scale of mineral hardness
. Almost all colors of corundum are called sapphire
s, except those of red corundum, which are called rubies
. The term "Yogo sapphire" refers only to sapphires from the Yogo Gulch. The unique cornflower blue color of the Yogo is provided by trace amounts of iron
and titanium
.
Yogo sapphires are unique among the world's sapphires: they lack color zoning, are free of cavities, do not need heat treating because their cornflower blue coloring is uniform and deep, are generally free of inclusions
, and they have high uniform clarity. Unlike Asian sapphires, they maintain their brilliance in artificial light. Because they are found in a lode
rather than alluvial deposits where most other sapphires are located, Yogos present an advantage to gemcutters: they retain a perfect or near-perfect crystalline shape, making the work of gem-cutting much easier, as does their lack of inclusions, color zoning, or cloudiness. Yogos also have a trigon
pattern, with rhombohedral crystals, a feature which is absent from sapphires from other parts of Montana. These rhombohedrons are almost always less than 1mm in thickness and appear like striations.
The United States Geological Survey
considers them among the world's finest sapphires. Some gem experts consider them the finest sapphires in the world. However, Yogo roughs tend to be small and flat, so large cut Yogo gems over two carats are rare. Only about 10% of cut pieces are over one carat. The largest recorded Yogo rough, found in 1910, was 19 carats in size, and was cut into an 8 carat gem. Yogos tend to be beautiful, small, and very expensive. Due to the rarity of large rough, prices for gems begin rising sharply when they are over a half carat, and skyrocket when they are over one carat. About 2% of Yogos are in colors other than blue, almost always purple, very rarely reddish. Sapphires found in the other parts of Montana come in a variety of colors, though rubies are rare. It is believed that the reason Yogos are almost always blue rather than coming in as wide variety of colors as other Montana sapphires is that their bedrock had a much longer cooling time. The largest cut Yogo is a 10.2 carat gem held by the Smithsonian Institution
.
The Yogo sapphire deposit is located in a silica-poor lamproite
igneous rock
dike cutting into limestone
that intruded a fissure into the earth. It varies from a few feet to almost 100 feet (30.5 m) in width, averaging 8 feet (2.4 m) wide, is over 5 miles (8 km) long, and at least 7000 feet (2,133.6 m) deep. It contains large amounts of biotite
and pyroxene
. Except for Yogo Gulch and one small site in Kashmir
, most other corundum is mined from the sand and gravel created by the weathering of metamorphic rock
. These alluvial sapphires are found in the Orient, Australia, and other Montana locations—the Missouri River
, Rock Creek
, and Dry Cottonwood Creek
.
There had been considerable debate over the years about how deep the Yogo dike was and how many ounces of sapphire rough per ton it contained, or "ounces per ton". In the late 1970s and early 1980s Delmer L. Brown, a geological engineer and gemologist, conducted the most thorough scientific exploration of the dike to date and showed it was at least 7000 feet (2,133.6 m) deep and that the amount of sapphire rough was not consistent throughout the deposit. He determined that the dike's erosion was minimal and recent. Brown also showed that the unique characteristics of the Yogo sapphires were due to the way they were formed. Most sapphires are formed under low pressure and temperature over geologically short periods of time, and this is why most non-Yogo sapphires have imperfections and inconsistent coloring. Yogos show crystalline formation over very high temperatures and pressures over geologically long periods of time. These conditions are only possible at great depth. Yogos were formed at great depths, at least thousands of feet, perhaps miles deep, and then carried upwards by slowly thickening magma. As sapphires are heavier then magma, the smaller roughs rose closer to the surface. This is why the Yogos found to date are generally small. Mining at the English Mine confirmed this as the deeper the digging there got, the more likely miners were to find bigger Yogo roughs. Brown also showed that distribution of gem rough through the dike was not consistent, so using an average "ounces per ton" was misleading. What came to be known as the American Mine was built at a part of the dike with significantly lower "ounces per ton" than the English Mine. As a result of Brown's findings, operations at the American Mine were permanently shut down.
. Garnet
s are also found at some Montana sapphire sites, inspiring the name of the Garnet Range
, which lies to the north of the Sapphire Mountains.
The first Sapphires found in the United States were discovered on May 5, 1865 along the Missouri River
about 14 miles east of Helena, Montana
in Lewis and Clark County, Montana
by Ed "Sapphire" Collins. Although Collins sent his find to Tiffany's
in New York City and Amsterdam for evaluation, the sapphires he sent did not have very good color or overall quality, so they garnered little notice and initially gave Montana sapphires a bad name. Corundum was also found at Dry Cottonwood Creek near Butte
in 1889, Rock Creek near Philipsburg
in 1892, and Quartz Gulch near Bozeman
in 1894. By 1890, the British-owned Sapphire and Ruby Mining Company had bought several thousand acres of land where Montana sapphires were found, but the venture failed after a few years due to fraud perpetrated by the owners.
Sapphires from these three sites are routinely heat treated to enhance color. While millions of carats of sapphires have been mined from the Missouri River deposits, there has been little activity there since the 1990s due to recovery costs and environmental concerns, though small scale "pan-your-own" operations allowing individuals to prospect for sapphires remain in operation. Production at Dry Cottonwood Creek has been sporadic and low-yielding. The Rock Creek area, also known as Gem Mountain, has been the most productive site in Montana by far, even more so than Yogo Gulch, producing over 190 million carats of sapphires.
. During the Montana Gold Rush
of 1878, about one thousand men came to Yogo Creek as a result of a gold strike; Yogo Creek being one of the gold-bearing streams in Montana that had not been actively mined. The mining camp of Yogo City flourished for about three years, but only bits of gold and "blue pebbles" were found. Thus, the population dwindled until only a few people were left.
While on a weight-for-weight basis sapphires are worth more than gold, and the Yogo mines ultimately produced more dollar value than several gold strikes, production of Yogos require hard rock mining and sophisticated marketing, whereas gold was easier to identify and merely required digging and selling. Nonetheless, sapphire mining at Yogo Gulch began in 1895 when someone finally thought to investigate the nature of the "blue pebbles." In that year, Jake Hoover sent a cigar box containing those he had collected while mining gold to an assay office, which in turn sent them via regular, uninsured mail to Tiffany's in New York City for appraisal by gemologist Dr. George Frederick Kunz
, the leading American gemologist of the time. Impressed by their quality and color, Kunz pronounced them “the finest precious gemstones ever found in the United States". Tiffany's sent Hoover a check for $3,750 along with a letter that described the blue pebbles as “sapphires of unusual quality.” In February 1896, sheepherder Jim Ettien found the sapphire mother lode
, the Yogo dike, while following a line of gopher holes. He sold it to Hoover. Hoover in turn sold his interest in his eight original mining stakes, known as the "New Mine Sapphire Syndicate," to his two partners for $5,000. For several years prior to discovering Yogo sapphires, Hoover had a ranch in Pig-Eye Basin. Afterwards he prospected for gold in Alaska
and was a deep-sea fishing guide in Seattle, before eventually returning to the Judith Basin.
On July 4, 1896, two other Americans, John Burke and Pat Sweeney, staked mining claims at six sections of western portion of the Yogo dike; areas Hoover had deemed unfit for mining. These claims were known as the "Fourth of July Claim". This mine became known as the "American Mine", bought in 1904 by the American Gem Syndicate and purchased in 1907 by the American Sapphire Company.
Millie Ringold, a former slave born in 1845, had settled in Fort Benton, Montana
after having worked as a nurse and servant for an army general. Millie promptly left for the Yogo gold fields, selling her boarding house in Fort Benton and setting up a hotel, restaurant, and saloon. She also sang and played music. Millie became known as a superb cook at the English Mine, but by 1903 she had fallen on hard times. She remained there until she died in 1906, was considered Yogo City's most prominent citizen, and ultimately the last resident of the city. Yogo City also was briefly known as Hoover City, after Jake Hoover, who employed and remained lifelong friends with western painter Charles Marion Russell
. Russell stated he learned most of his frontier skills from Hoover. The nearby town of Utica was featured in Russell's 1907 painting A Quiet Day in Utica, which was originally known as Tinning a Dog. Russell himself, Hoover, and Ringold are all depicted in the painting.
In 1899, gem merchants Johnson, Walker and Tolhurst, Ltd. of London paid $100,000 for the New Mine Sapphire Syndicate, which then became unofficially known as the "English Mine." This site was 5 miles (8 km) from Yogo City. One of the Englishmen who came to the area was Charles Gadsden of Berkhamsted
. By 1900, there was little left of the gold mine, though Ringold was still working gold claims. By 1902, Gadsden was promoted to resident supervisor of the English Mine and he quickly turned the mine's focus to sapphires. Weight-for-weight rough sapphires are worth much more than gold, and Gadsden's security measures were very tight. The English Mine flourished until the 1920s. Floods so severely damaged the mines on July 26, 1923 that they never fully recovered. The "English Mine" finally succumbed to the aftermath of the floods and hard economic times in 1929. It had recovered more than 16 million carats of rough sapphires that were valued at $2.5 million. Subsequently a series of several other firms mined the sapphires but with marginal success.
Operations at the English Mine were significantly more profitable than at the American Mine, largely because of the mining and management techniques employed, insufficient space and water for ore weathering at their end of the Yogo dike, and inability to market the gems within the United States. Roughs from the English Mine were shipped to London and sold in Europe, often as sapphires from the Far East. The American Sapphire Company, which used less skilled gemcutter
s from Great Falls, Montana
, went bankrupt in 1909 and a new form, the Yogo American Sapphire Company bought the American Mine but went bankrupt in 1913. The American Mine was then bought by New Mine Sapphire Syndicate in 1914, which quickly recouped its purchase price by washing the tailings left behind by the American Mine. Sapphire mining at the other Montana sapphire mines was even less successful because of the very low profit margin in sapphires that are not blue. Blue sapphires are extremely rare at Montana sites other than Yogo Gulch.
Other Montana sapphires were heavily mined during World War II
for industrial uses. However, because the Yogo mines were still owned by the British, they were little affected by the war. Hoover remained caretaker of the mines until shortly before his death on March 11, 1954. For much of the 1930s and 1940s he was the sole employee of the mine and spent $29,000 of his own money to pay the mine's property taxes. The sixth American company to acquire the Yogo dike was the Yogo Sapphire Mining Corporation of Billings, Montana
. The firm made its initial offer in 1946 and obtained an agreement with the English in 1949. However, legal wrangling delayed the actual purchase until July 1956. The final price was $65,000 and various stock considerations. Like so many other Yogo ventures, its capital was exhausted. The Yogo Sapphire Mining Corporation then changed its name to the same as the British firm's name: New Mine Sapphire Syndicate. It became known as the "American Syndicate" to distinguish it from the previous "English Syndicate". Production was poor and mining ceased in September 1959. From 1959–1963 the mine was "open" resulting in hobbyists, picknickers, and rockhounds from all over America and Canada coming to gather loose rough. The American Syndicate finally took action to stop this in 1963, with fences and threats of prosecution. The American Syndicate had leased the mine to several operators. One of these was Siskon, Inc. of Nevada, who lost a significant amount of money. They sued and in May 1965 the Montana Supreme Court ruled in Siskon's favor. Siskon bought the mine at a sheriff's sale and in turn leased it to a group headed by Arnold Baron, who had a background in gemcutting and jewelry. Baron organized some German and Thai gemcutters and had success in marketing Yogos in America—the first time that occurred in 50 years. However, due to the difficulty in mining the hard rock site, he did not exercise his option to buy the mine and Siskon sold it in August 1968 when Herman Yaras bought it for $585.000.
Yaras' firm was called Sapphire Village, Inc. Yaras was from Oxnard, California
. This eventually led to what is now called Sapphire Village in early 1969, a nearby homesite development where people can gather their own sapphires through limited mining rights. "Mining" on these homesites was limited to hand tools. Meanwhile, Sapphire Village, Inc. did little to mine and market sapphires and it folded. Yaras sold the mine in 1973 to Chikara Kunisaki, an Oxnard, California native and celery farmer. Kunisaki owned one of the original homes in Sapphire Village and named his firm Sapphire International Corporation. Kunisaki then made the first serious effort to mine Yogo Gulch since the early days of the English Mine. He built a modern 3,000 foot tunnel at the site of the old American Mine that became known as the "Kunisaki Tunnel". However, Sapphire International Corporation's operations were so costly that it shut down operations in fall 1976.
Victor di Suvero and his firm Sapphire-Yogo Mines were next in January 1977 with a lease on the mine. Di Suvero was a native-born Italian who grew up in Tientsin, China and had been successful with a jade mine in California. Di Suvero's expertise was in marketing and he formed Sapphire Trading to cut and market the Yogos. He had novel marketing ideas but neglected the mining aspects of business. Consequently he was unable to make payments and this venture folded in fall 1979. At this point, only 4 Americans had been successful at Yogo Gulch and that was early in its mining history. At least thirteen American Yogo mining efforts had failed. Besides financial and hard rock mining difficulties, the Americans did not understand gem marketing. They generally approached the Yogos as if they were gold nuggets; not being able to see past a bag full of sapphire roughs.
Kunisaki then put his mine up for sale, asking $6 million to recoup his expenses. Even though mine profits had been poor over the decades, during this time prices of precious gems were very high due to the world wide oil crises of the 1970s and early 1980s. Four individuals or groups seriously considered Kunisaki's offer. Relying heavily upon the expertise of Brown, Harry C. Bullock and J. R. Edington formed the limited partnership American Yogo Sapphire Limited, the 14th American company to work the Yogo dike. They paid the $6 million price and then raised $7.2 million in funding by October 1981. Bullock and Brown had Yogo mine experience prior to this as they had worked with di Suvero. Bullock's plan included mining, cutting, making jewelry, and marketing—the whole specturm of the business. Brown discovered he could get the best gemcutters for the best price, who were also willing to improve their skills, in Thailand
. This is where American Yogo Sapphire Limited set up its network of cutters. Brown also set up a security system that was computerized, thorough, and started at the mine and included the Thai cutters. Bigger roughs were sent to American cutters, specialty cuts were done in Germany, and a few cuts were done in Hong Kong. The vast majority of cuts were done in Thailand. American Yogo Sapphire Limited secured a $5 million line of credit with Citibank
. Desiring a more modern name, American Yogo Sapphire Limited changed its name to Intergem Limited in spring 1982. Intergem marketed the Yogo as the Royal American Sapphire. Their first line of jewelry appeared in late summer 1982. Intergem started by marketing the jewelry regionally in the American west and then national marketing. They also developed a system of authorized dealers. Intergem began marketing the Yogo, rather Royal American Sapphire, as the world's only guaranteed untreated sapphire—a claim which rocked the gem trade because by 1982 the issue of heat treating gems had become a major issue in the gem trade. At that time 95% of all the world's sapphires were being heated to enhance their natural color. The Thais had taken this a step further by buying large quantities of Sri Lankan sapphires that were naturally colorless, known as geuda
, and heating them to a totally artificial blue. Compounding the problem, heated gems often fade over time. Trained gemologists can detect a heated gem 95% of the time. Intergem's marketing of guaranteed untreated Yogos set them against many in the gem industry. This issue appeared as a front page story in the Wall Street Journal on August 29, 1984 in an article by Bill Richards entitled "Carats and Schticks: Sapphire Marketer Upsets The Gem Industry". In its first 4 years Intergem met with success. In 1984 alone sales were over $3 million. In 1985 there was a movement in Pennsylvania to require disclosure that a gem had been treated. Large numbers of gem professionals were visiting Yogo Gulch. However, problems were brewing.
Intergem had begun planning to dig even deeper into the Yogo dike; which held more known reserves than all the world's other known sapphire deposits combined; albeit deep underground than near the surface like the other known deposits. By this time Sapphire International Corporation had been renamed to Roncor; to which Intergem had made a down payment and agreed to make semi-annual payments. Intergem also had loan and interest payments to make to Citibank. Intergem's sales were steadily increasing, but even still not enough cash was coming in and in May 1985 they missed a $250,000 payment to Roncor. Their collateral with Citibank had declined because their collateral was their own inventory and the value of gems was declining. Citibank called in its loan. Intergem had over $1 million in sales lined up for the 1985 Christmas season but could only fill a tiny portion. In summer 1986 Roncor regained full ownership even though Intergem had sold carats and jewelry worth millions of dollars.
While the various companies attempted mine leasing with Roncor, two local married couples discovered a new site at Yogo Gulch in January 1984 by following a trail to an unused section of the dike that had previously been deemed unsuitable. They began mining the site and named it the "Vortex Mine". The company was named Vortex Mining. The mine shaft went 280 feet (85.3 m) down and contained two Yogo ore-bearing veins. The mine was successful for years but eventually declined and the Vortex Mine, which was now called Yogo Creek Mining, closed in 2004. The portion of the dike they had mined was an extension of the main dike. In 1992 Roncor found an 11 carat rough.
AMAX Exploration, operating as the Yogo Sapphire Project, signed a 22-month lease with Roncor in March 1993 and had some success in the middle and eastern portions of the dike but decided not to continue after the end of its lease due to the cost of underground mining, depletion of easily accessible Yogos, and the relatively small size of Yogos currently easily accessible. During this time additional dikes were found in the area and low grade rough was found in what is known as the "Eastern Flats Dike".
In 1995 Intergem's stock of gems began to reappear on the market because during its demise Intergem had paid its salesmen in sapphires. After Intergem collapsed, many of its salesmen continued to sell Yogos, especially after AMAX ceased operations. Citibank also had obtained a large stock of Yogo pieces as a result of Intergem's demise reputedly worth $3.5 million and consisting of 200,000 carats of rough, 22,000 carats of cut gems, and 2,000 pieces of jewelry. This sat in the bank's vaults until 1991 when Sofus Michelsen, director of the Center for Gemstone Evaluation and creator of the Michelsen Gemstone Index, became interested. In 1992 he and Jim Adair, a Missoula, Montana
jeweler who is the world's largest retailer of Yogos, got together and by October 1994 Adair had purchased most of Yogo material Citibank had, which had been stored in 4 sealed bags, which contained a lot of dirt. Only one of the bags was truly valuable. Adair and Michelsen designed custom cutting techniques for Yogos. Then a Canadian company called Pacific Cascade Sapphires operated a mining lease from Roncor in 2000 and 2001 but ran out of funds before becoming successful and their option expired. By this time most of the easily accessible Yogos had been mined and miners were having to dig deeper; further increasing costs.
A new owner bought Vortex in 2008 and is in operation as of late 2011. Its operations are environmentally friendly, using methods such as recycling all water and not using chemicals. As of 2011, there is also mining activity at Sapphire Village, though the Roncor mines are inactive.
s. Agates were chosen due to their great abundance, particularly in the Yellowstone River
basin, which flows from Yellowstone National Park
north to Livingston
, then east through Montana until its confluence with the Missouri just over the state's boundary with North Dakota. Finally, in 1969, these gems were jointly declared the state gemstones.
. The first were noted in its annual report for the year ending June 30, 1899, when the Smithsonian reported that Dr. L. T. Chamberlain gave them 2 cut Yogos and 21 other sapphires, as well as other gems, for its Dr. Isaac Lea
gem and mineral collection. In 2006, a representative of the Smithsonian Institution asked Paula Crevoshay, a jewelry designer from Albuquerque, New Mexico
, if she would take a set of sapphires from Montana and create a piece of finished jewelry. The gems in question were being donated to the Smithsonian's Gem and Mineral Collection by gemologist Robert Kane of Fine Gems International in Helena, Montana
, which has the largest selection of Montana sapphires in the world. He provided 333 Montana sapphires weighing 27.97 carats along with 98.48 grams of 18K yellow gold for the project. Crevoshay felt that a butterfly motif would be excellent to represent America's natural beauty, honor her mother's love of butterflies, and display the wide range of colors found in Montana sapphires. Crevoshay named the brooch "Conchita" in honor of her mother. It is also referred to as the "Sapphire Butterfly Brooch", "Conchita Sapphire Butterfly", and the "Montana Butterfly Brooch". The brooch can also be worn as a pendant or clasp and can be beaded. Two of the sapphires used are cabochon
cut and the rest are brilliant cut. Most are from the Rock Creek deposit. The largest one, however, is a blue Yogo used for the butterfly's head. Other colors used are yellow, purple, pink, and orange. Crevoshay and Kane presented it to Smithsonian curator Jeffrey Post on May 7, 2007 in Washington, D. C.
In the earliest years of Yogo sapphire mining, before Yogos achieved their own reputation, Oriental sapphires were sold in Montana with claims they were Yogos while in Europe Yogos were sold with claims of being Oriental sapphires. However, they became notable in their own right. Paulding Farnham (1859–1927) used these stones to great advantage in several jewelry pieces he designed for the 1900 Exposition Universelle
in Paris
, where Yogo sapphires received a silver medal for color and clarity. Yogo sapphires also won a bronze medal at the 1904 Louisiana Purchase Exposition
in St. Louis, Missouri
. The most elaborate piece of jewelry ever made with Yogos is the Tiffany Iris Brooch that was designed by Farnham and contains 120 Yogo sapphires. The Tiffany Iris Brooch was first sold on March 17, 1900 for $6,906.84. In 1923 First Lady
Florence Harding
was given an "all Montana" ring made from a Yogo sapphire and Montana gold. In 1952 Gadsden gave cut Yogos to President Harry Truman, his wife Bess Truman
, and their daughter Margaret Truman
. While there is no doubt many Yogos have been sold in Europe, there is dispute about whether they are in any of the crown jewels of Europe or whether Lady Diana Spencer
's engagement ring sapphire was a Yogo. This same ring was also Kate Middleton's engagement ring. That sapphire has been reported as being 9, 12, and 18 carats.
Cornflower blue
Cornflower blue, a shade of azure, is a shade of light blue with relatively little green compared to blue. This color was one of the favorites of the Dutch painter Johannes Vermeer, the other being yellow....
color variety of corundum
Corundum
Corundum is a crystalline form of aluminium oxide with traces of iron, titanium and chromium. It is a rock-forming mineral. It is one of the naturally clear transparent materials, but can have different colors when impurities are present. Transparent specimens are used as gems, called ruby if red...
found only in Yogo Gulch, Judith Basin County, Montana
Judith Basin County, Montana
-Demographics:As of the census of 2000, there were 2,329 people, 951 households, and 661 families residing in the county. The population density was -Demographics:...
, United States. They are considered among the finest sapphire
Sapphire
Sapphire is a gemstone variety of the mineral corundum, an aluminium oxide , when it is a color other than red or dark pink; in which case the gem would instead be called a ruby, considered to be a different gemstone. Trace amounts of other elements such as iron, titanium, or chromium can give...
s in the world, and by some gem experts, the finest. Sapphire mining at Yogo Gulch began in 1895, and the term "Yogo" is said to mean "blue sky" in the Piegan Blackfeet language. About $25 million of gemstone has been recovered by all mines at Yogo, and at least 28 million carat
Carat (mass)
The carat is a unit of mass equal to 200 mg and is used for measuring gemstones and pearls.The current definition, sometimes known as the metric carat, was adopted in 1907 at the Fourth General Conference on Weights and Measures, and soon afterward in many countries around the world...
s are estimated to still be in the ground.
The cornflower blue color of the Yogo is provided by trace amounts of iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
and titanium
Titanium
Titanium is a chemical element with the symbol Ti and atomic number 22. It has a low density and is a strong, lustrous, corrosion-resistant transition metal with a silver color....
. While sapphires were first discovered in Montana in 1865 it was not until 1895 that their quality and value was noticed and serious mining efforts began. Due to the unique nature of the dike that Yogo sapphires are found in, mining efforts at Yogo Gulch have been sporadic and rarely profitable. Yogo sapphires are rarer than diamonds. In 1969 the sapphire was designated the Montana state gemstone, along with Montana agate
Agate
Agate is a microcrystalline variety of silica, chiefly chalcedony, characterised by its fineness of grain and brightness of color. Although agates may be found in various kinds of rock, they are classically associated with volcanic rocks and can be common in certain metamorphic rocks.-Etymology...
.
Location
Judith Basin County, Montana
-Demographics:As of the census of 2000, there were 2,329 people, 951 households, and 661 families residing in the county. The population density was -Demographics:...
, 12 miles (19.3 km) southwest (SW) of Utica, Montana and 45 miles (72.4 km) west-southwest (WSW) of Lewistown, Montana
Lewistown, Montana
Lewistown is a city in and the county seat of Fergus County, Montana, United States. The population was 5,813 at the 2000 census. Lewistown is located in central Montana, the geographic center of the state, southeast of Great Falls...
. It lies east of Great Falls, Montana
Great Falls, Montana
Great Falls is a city in and the county seat of Cascade County, Montana, United States. The population was 58,505 at the 2010 census. It is the principal city of the Great Falls, Montana Metropolitan Statistical Area, which encompasses all of Cascade County...
. The area where Yogo sapphires are mined is a region historically inhabited by the Piegan Blackfeet people, and the word "Yogo" is alleged to mean "blue sky" in Piegan Blackfeet, although there is some dispute about this translation. At the time of discovery, this area was in southwestern Fergus County, Montana
Fergus County, Montana
-National protected areas:* Charles M. Russell National Wildlife Refuge * Lewis and Clark National Forest * Upper Missouri River Breaks National Monument -Demographics:...
. Yogo Gulch and Utica are now located in Judith Basin County, which was broken out from western Fergus County and eastern Cascade County, Montana
Cascade County, Montana
-National protected areas:*Benton Lake National Wildlife Refuge*Lewis and Clark National Forest -Economy:Malmstrom Air Force Base is a driving force in the regional economy...
on December 10, 1920. Yogo Peak (el. 8625 feet (2,628.9 m)), Yogo Creek, Yogo Gulch, and the Yogo dike are located in the portion of the Little Belt Mountains
Little Belt Mountains
The Little Belt Mountains are a section of the Rocky Mountains in the U.S. state of Montana. Situated mainly in the Lewis and Clark National Forest, the mountains are used for logging and recreation for the residents of Great Falls, Montana...
that lies within Judith Basin County. The Judith River
Judith River
The Judith River is a tributary of the Missouri River, approximately 124 mi long, running through central Montana and the United States. It rises in the Little Belt Mountains and flows northeast past Utica and Hobson...
flows northeast out of the Little Belts towards Utica. East of the river is Pig-Eye Basin—where Jake Hoover, claimed to be the discoverer of Yogo sapphires, had a ranch. The Yogo area to the west. Yogo Peak is about 15 miles (24.1 km) west of the Judith River
Judith River
The Judith River is a tributary of the Missouri River, approximately 124 mi long, running through central Montana and the United States. It rises in the Little Belt Mountains and flows northeast past Utica and Hobson...
. Yogo Creek originates there and flows southeast to its confluence with the Middle Fork of the Judith River a few miles upstream of where the Middle Fork joins the Judith. Yogo Gulch is located along the lower reaches of Yogo Creek, and the Yogo dike originates a few miles north of the stream's confluence, then runs from west-southwest to east-northeast from Yogo Creek to just before the Judith River.
Mineralogy
Most sapphires found at Yogo Gulch must be mined from hard rock, "in situ". This, plus American labor costs, makes mining Yogos fairly expensive, and keeps them rarer than diamonds. About $25 million of gemstone has been recovered by all mines at Yogo to date. However, at least 28 million carats are estimated to still be in the ground.Sapphires are a form of corundum
Corundum
Corundum is a crystalline form of aluminium oxide with traces of iron, titanium and chromium. It is a rock-forming mineral. It is one of the naturally clear transparent materials, but can have different colors when impurities are present. Transparent specimens are used as gems, called ruby if red...
, which is crystalline aluminum oxide and its chemical formula is Al2O3. Corundum is the second hardest mineral (rating 9) on the Mohs scale of mineral hardness
Mohs scale of mineral hardness
The Mohs scale of mineral hardness characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer material. It was created in 1812 by the German geologist and mineralogist Friedrich Mohs and is one of several definitions of hardness in...
. Almost all colors of corundum are called sapphire
Sapphire
Sapphire is a gemstone variety of the mineral corundum, an aluminium oxide , when it is a color other than red or dark pink; in which case the gem would instead be called a ruby, considered to be a different gemstone. Trace amounts of other elements such as iron, titanium, or chromium can give...
s, except those of red corundum, which are called rubies
Ruby
A ruby is a pink to blood-red colored gemstone, a variety of the mineral corundum . The red color is caused mainly by the presence of the element chromium. Its name comes from ruber, Latin for red. Other varieties of gem-quality corundum are called sapphires...
. The term "Yogo sapphire" refers only to sapphires from the Yogo Gulch. The unique cornflower blue color of the Yogo is provided by trace amounts of iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
and titanium
Titanium
Titanium is a chemical element with the symbol Ti and atomic number 22. It has a low density and is a strong, lustrous, corrosion-resistant transition metal with a silver color....
.
Yogo sapphires are unique among the world's sapphires: they lack color zoning, are free of cavities, do not need heat treating because their cornflower blue coloring is uniform and deep, are generally free of inclusions
Inclusion (mineral)
In mineralogy, an inclusion is any material that is trapped inside a mineral during its formation.In gemology, an inclusion is a characteristic enclosed within a gemstone, or reaching its surface from the interior....
, and they have high uniform clarity. Unlike Asian sapphires, they maintain their brilliance in artificial light. Because they are found in a lode
Lode
In geology, a lode is a deposit of metalliferous ore that fills or is embedded in a fissure in a rock formation or a vein of ore that is deposited or embedded between layers of rock....
rather than alluvial deposits where most other sapphires are located, Yogos present an advantage to gemcutters: they retain a perfect or near-perfect crystalline shape, making the work of gem-cutting much easier, as does their lack of inclusions, color zoning, or cloudiness. Yogos also have a trigon
Triangle
A triangle is one of the basic shapes of geometry: a polygon with three corners or vertices and three sides or edges which are line segments. A triangle with vertices A, B, and C is denoted ....
pattern, with rhombohedral crystals, a feature which is absent from sapphires from other parts of Montana. These rhombohedrons are almost always less than 1mm in thickness and appear like striations.
The United States Geological Survey
United States Geological Survey
The United States Geological Survey is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The organization has four major science disciplines, concerning biology,...
considers them among the world's finest sapphires. Some gem experts consider them the finest sapphires in the world. However, Yogo roughs tend to be small and flat, so large cut Yogo gems over two carats are rare. Only about 10% of cut pieces are over one carat. The largest recorded Yogo rough, found in 1910, was 19 carats in size, and was cut into an 8 carat gem. Yogos tend to be beautiful, small, and very expensive. Due to the rarity of large rough, prices for gems begin rising sharply when they are over a half carat, and skyrocket when they are over one carat. About 2% of Yogos are in colors other than blue, almost always purple, very rarely reddish. Sapphires found in the other parts of Montana come in a variety of colors, though rubies are rare. It is believed that the reason Yogos are almost always blue rather than coming in as wide variety of colors as other Montana sapphires is that their bedrock had a much longer cooling time. The largest cut Yogo is a 10.2 carat gem held by the Smithsonian Institution
Smithsonian Institution
The Smithsonian Institution is an educational and research institute and associated museum complex, administered and funded by the government of the United States and by funds from its endowment, contributions, and profits from its retail operations, concessions, licensing activities, and magazines...
.
The Yogo sapphire deposit is located in a silica-poor lamproite
Lamproite
Lamproites are ultrapotassic mantle-derived volcanic and subvolcanic rocks. They have low CaO, Al2O3, Na2O, high K2O/Al2O3, a relatively high MgO content and extreme enrichment in incompatible elements....
igneous rock
Igneous rock
Igneous rock is one of the three main rock types, the others being sedimentary and metamorphic rock. Igneous rock is formed through the cooling and solidification of magma or lava...
dike cutting into limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
that intruded a fissure into the earth. It varies from a few feet to almost 100 feet (30.5 m) in width, averaging 8 feet (2.4 m) wide, is over 5 miles (8 km) long, and at least 7000 feet (2,133.6 m) deep. It contains large amounts of biotite
Biotite
Biotite is a common phyllosilicate mineral within the mica group, with the approximate chemical formula . More generally, it refers to the dark mica series, primarily a solid-solution series between the iron-endmember annite, and the magnesium-endmember phlogopite; more aluminous endmembers...
and pyroxene
Pyroxene
The pyroxenes are a group of important rock-forming inosilicate minerals found in many igneous and metamorphic rocks. They share a common structure consisting of single chains of silica tetrahedra and they crystallize in the monoclinic and orthorhombic systems...
. Except for Yogo Gulch and one small site in Kashmir
Kashmir
Kashmir is the northwestern region of the Indian subcontinent. Until the mid-19th century, the term Kashmir geographically denoted only the valley between the Great Himalayas and the Pir Panjal mountain range...
, most other corundum is mined from the sand and gravel created by the weathering of metamorphic rock
Metamorphic rock
Metamorphic rock is the transformation of an existing rock type, the protolith, in a process called metamorphism, which means "change in form". The protolith is subjected to heat and pressure causing profound physical and/or chemical change...
. These alluvial sapphires are found in the Orient, Australia, and other Montana locations—the Missouri River
Missouri River
The Missouri River flows through the central United States, and is a tributary of the Mississippi River. It is the longest river in North America and drains the third largest area, though only the thirteenth largest by discharge. The Missouri's watershed encompasses most of the American Great...
, Rock Creek
Rock Creek (Montana)
Rock Creek is a river in Missoula and Granite County, Montana. Rock Creek is a tributary of the Clark Fork river. The river's headwaters are in Lolo National Forest near Phillipsburg, Montana. The river roughly parallels the Sapphire Mountains and enters the Clark Fork near Clinton, Montana...
, and Dry Cottonwood Creek
Dry Cottonwood Creek (Deer Lodge County, Montana)
Dry Cottonwood Creek is a creek in Deer Lodge County, Montana. Approximately long, it flows northwest out of the southern reaches of the Boulder Mountains into the Clark Fork river near Deer Lodge, Montana. Sapphires are found along this creek....
.
There had been considerable debate over the years about how deep the Yogo dike was and how many ounces of sapphire rough per ton it contained, or "ounces per ton". In the late 1970s and early 1980s Delmer L. Brown, a geological engineer and gemologist, conducted the most thorough scientific exploration of the dike to date and showed it was at least 7000 feet (2,133.6 m) deep and that the amount of sapphire rough was not consistent throughout the deposit. He determined that the dike's erosion was minimal and recent. Brown also showed that the unique characteristics of the Yogo sapphires were due to the way they were formed. Most sapphires are formed under low pressure and temperature over geologically short periods of time, and this is why most non-Yogo sapphires have imperfections and inconsistent coloring. Yogos show crystalline formation over very high temperatures and pressures over geologically long periods of time. These conditions are only possible at great depth. Yogos were formed at great depths, at least thousands of feet, perhaps miles deep, and then carried upwards by slowly thickening magma. As sapphires are heavier then magma, the smaller roughs rose closer to the surface. This is why the Yogos found to date are generally small. Mining at the English Mine confirmed this as the deeper the digging there got, the more likely miners were to find bigger Yogo roughs. Brown also showed that distribution of gem rough through the dike was not consistent, so using an average "ounces per ton" was misleading. What came to be known as the American Mine was built at a part of the dike with significantly lower "ounces per ton" than the English Mine. As a result of Brown's findings, operations at the American Mine were permanently shut down.
Montana sapphires
The term "Montana sapphire" generally refers to gems from Montana locations other than Yogo Gulch, where "Yogo sapphires" is the preferred term. More gem-quality sapphires are produced in Montana than anywhere else in North America. These gems inspired the names of geologic features; the mountains near Rock Creek are known as the Sapphire MountainsSapphire Mountains
The Sapphire Mountains are a range of mountains located in southwestern Montana in the northwestern United States. From a point near the Clark Fork River and the city of Missoula, they run in a southerly direction for a distance of approximately 60 miles , making up much of the border between...
. Garnet
Garnet
The garnet group includes a group of minerals that have been used since the Bronze Age as gemstones and abrasives. The name "garnet" may come from either the Middle English word gernet meaning 'dark red', or the Latin granatus , possibly a reference to the Punica granatum , a plant with red seeds...
s are also found at some Montana sapphire sites, inspiring the name of the Garnet Range
Garnet Range
The Garnet Range, highest point Old Baldy Mountain, elevation , is a mountain range northeast of Drummond, Montana in Powell County, Montana....
, which lies to the north of the Sapphire Mountains.
The first Sapphires found in the United States were discovered on May 5, 1865 along the Missouri River
Missouri River
The Missouri River flows through the central United States, and is a tributary of the Mississippi River. It is the longest river in North America and drains the third largest area, though only the thirteenth largest by discharge. The Missouri's watershed encompasses most of the American Great...
about 14 miles east of Helena, Montana
Helena, Montana
Helena is the capital city of the U.S. state of Montana and the county seat of Lewis and Clark County. The 2010 census put the population at 28,180. The local daily newspaper is the Independent Record. The Helena Brewers minor league baseball and Helena Bighorns minor league hockey team call the...
in Lewis and Clark County, Montana
Lewis and Clark County, Montana
-National protected areas:* Flathead National Forest * Helena National Forest * Lewis and Clark National Forest * Lolo National Forest * Rocky Mountain Front Conservation Area -Demographics:...
by Ed "Sapphire" Collins. Although Collins sent his find to Tiffany's
Tiffany's
Tiffany's Restaurants, Inc. is a restaurant chain with 6 locations in New Jersey. Its flagship location was opened at Union, New Jersey in 1982 as Tiffany Gardens.-Reviews:...
in New York City and Amsterdam for evaluation, the sapphires he sent did not have very good color or overall quality, so they garnered little notice and initially gave Montana sapphires a bad name. Corundum was also found at Dry Cottonwood Creek near Butte
Butte, Montana
Butte is a city in Montana and the county seat of Silver Bow County, United States. In 1977, the city and county governments consolidated to form the sole entity of Butte-Silver Bow. As of the 2010 census, Butte's population was 34,200...
in 1889, Rock Creek near Philipsburg
Philipsburg, Montana
Philipsburg is a town in and the county seat of Granite County, Montana, United States. The population was 914 at the 2000 census. The town was named after the famous mining engineer Philip Deidesheimer, who designed and supervised the construction of the ore smelter around which the town...
in 1892, and Quartz Gulch near Bozeman
Bozeman, Montana
Bozeman is a city in and the county seat of Gallatin County, Montana, United States, in the southwestern part of the state. The 2010 census put Bozeman's population at 37,280 making it the fourth largest city in the state. It is the principal city of the Bozeman micropolitan area, which consists...
in 1894. By 1890, the British-owned Sapphire and Ruby Mining Company had bought several thousand acres of land where Montana sapphires were found, but the venture failed after a few years due to fraud perpetrated by the owners.
Sapphires from these three sites are routinely heat treated to enhance color. While millions of carats of sapphires have been mined from the Missouri River deposits, there has been little activity there since the 1990s due to recovery costs and environmental concerns, though small scale "pan-your-own" operations allowing individuals to prospect for sapphires remain in operation. Production at Dry Cottonwood Creek has been sporadic and low-yielding. The Rock Creek area, also known as Gem Mountain, has been the most productive site in Montana by far, even more so than Yogo Gulch, producing over 190 million carats of sapphires.
Mining history
Although gold had first been discovered at Yogo Creek in 1866, the early prospectors were chased off by local Native AmericansIndigenous peoples of the Americas
The indigenous peoples of the Americas are the pre-Columbian inhabitants of North and South America, their descendants and other ethnic groups who are identified with those peoples. Indigenous peoples are known in Canada as Aboriginal peoples, and in the United States as Native Americans...
. During the Montana Gold Rush
Gold rush
A gold rush is a period of feverish migration of workers to an area that has had a dramatic discovery of gold. Major gold rushes took place in the 19th century in Australia, Brazil, Canada, South Africa, and the United States, while smaller gold rushes took place elsewhere.In the 19th and early...
of 1878, about one thousand men came to Yogo Creek as a result of a gold strike; Yogo Creek being one of the gold-bearing streams in Montana that had not been actively mined. The mining camp of Yogo City flourished for about three years, but only bits of gold and "blue pebbles" were found. Thus, the population dwindled until only a few people were left.
While on a weight-for-weight basis sapphires are worth more than gold, and the Yogo mines ultimately produced more dollar value than several gold strikes, production of Yogos require hard rock mining and sophisticated marketing, whereas gold was easier to identify and merely required digging and selling. Nonetheless, sapphire mining at Yogo Gulch began in 1895 when someone finally thought to investigate the nature of the "blue pebbles." In that year, Jake Hoover sent a cigar box containing those he had collected while mining gold to an assay office, which in turn sent them via regular, uninsured mail to Tiffany's in New York City for appraisal by gemologist Dr. George Frederick Kunz
George Frederick Kunz
George Frederick Kunz was an American mineralogist and mineral collector.- Overview :Kunz was born in New York City, USA, and began an interest in minerals at a very young age. By his teens, he had amassed a collection of over four thousand items, which he sold for four hundred dollars to the...
, the leading American gemologist of the time. Impressed by their quality and color, Kunz pronounced them “the finest precious gemstones ever found in the United States". Tiffany's sent Hoover a check for $3,750 along with a letter that described the blue pebbles as “sapphires of unusual quality.” In February 1896, sheepherder Jim Ettien found the sapphire mother lode
Mother Lode
Mother lode is a principal vein or zone of veins of gold or silver ore. The term probably came from a literal translation of the Spanish veta madre, a term common in old Mexican mining...
, the Yogo dike, while following a line of gopher holes. He sold it to Hoover. Hoover in turn sold his interest in his eight original mining stakes, known as the "New Mine Sapphire Syndicate," to his two partners for $5,000. For several years prior to discovering Yogo sapphires, Hoover had a ranch in Pig-Eye Basin. Afterwards he prospected for gold in Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
and was a deep-sea fishing guide in Seattle, before eventually returning to the Judith Basin.
On July 4, 1896, two other Americans, John Burke and Pat Sweeney, staked mining claims at six sections of western portion of the Yogo dike; areas Hoover had deemed unfit for mining. These claims were known as the "Fourth of July Claim". This mine became known as the "American Mine", bought in 1904 by the American Gem Syndicate and purchased in 1907 by the American Sapphire Company.
Millie Ringold, a former slave born in 1845, had settled in Fort Benton, Montana
Fort Benton, Montana
Fort Benton is a city in and the county seat of Chouteau County, Montana, United States. A portion of the city was designated as a National Historic Landmark District in 1961. Established a full generation beforethe U.S...
after having worked as a nurse and servant for an army general. Millie promptly left for the Yogo gold fields, selling her boarding house in Fort Benton and setting up a hotel, restaurant, and saloon. She also sang and played music. Millie became known as a superb cook at the English Mine, but by 1903 she had fallen on hard times. She remained there until she died in 1906, was considered Yogo City's most prominent citizen, and ultimately the last resident of the city. Yogo City also was briefly known as Hoover City, after Jake Hoover, who employed and remained lifelong friends with western painter Charles Marion Russell
Charles Marion Russell
Charles Marion Russell , also known as C. M. Russell, Charlie Russell, and "Kid" Russell, was an artist of the Old American West. Russell created more than 2,000 paintings of cowboys, Indians, and landscapes set in the Western United States, in addition to bronze sculptures...
. Russell stated he learned most of his frontier skills from Hoover. The nearby town of Utica was featured in Russell's 1907 painting A Quiet Day in Utica, which was originally known as Tinning a Dog. Russell himself, Hoover, and Ringold are all depicted in the painting.
In 1899, gem merchants Johnson, Walker and Tolhurst, Ltd. of London paid $100,000 for the New Mine Sapphire Syndicate, which then became unofficially known as the "English Mine." This site was 5 miles (8 km) from Yogo City. One of the Englishmen who came to the area was Charles Gadsden of Berkhamsted
Berkhamsted
-Climate:Berkhamsted experiences an oceanic climate similar to almost all of the United Kingdom.-Castle:...
. By 1900, there was little left of the gold mine, though Ringold was still working gold claims. By 1902, Gadsden was promoted to resident supervisor of the English Mine and he quickly turned the mine's focus to sapphires. Weight-for-weight rough sapphires are worth much more than gold, and Gadsden's security measures were very tight. The English Mine flourished until the 1920s. Floods so severely damaged the mines on July 26, 1923 that they never fully recovered. The "English Mine" finally succumbed to the aftermath of the floods and hard economic times in 1929. It had recovered more than 16 million carats of rough sapphires that were valued at $2.5 million. Subsequently a series of several other firms mined the sapphires but with marginal success.
Operations at the English Mine were significantly more profitable than at the American Mine, largely because of the mining and management techniques employed, insufficient space and water for ore weathering at their end of the Yogo dike, and inability to market the gems within the United States. Roughs from the English Mine were shipped to London and sold in Europe, often as sapphires from the Far East. The American Sapphire Company, which used less skilled gemcutter
Gemcutter
A gemcutter, is a person who cuts, shapes, and polishes natural and synthetic gemstones. In historical use it usually refers to an artist who made hardstone carvings or engraved gems, a branch of miniature sculpture or ornament in gemstone....
s from Great Falls, Montana
Great Falls, Montana
Great Falls is a city in and the county seat of Cascade County, Montana, United States. The population was 58,505 at the 2010 census. It is the principal city of the Great Falls, Montana Metropolitan Statistical Area, which encompasses all of Cascade County...
, went bankrupt in 1909 and a new form, the Yogo American Sapphire Company bought the American Mine but went bankrupt in 1913. The American Mine was then bought by New Mine Sapphire Syndicate in 1914, which quickly recouped its purchase price by washing the tailings left behind by the American Mine. Sapphire mining at the other Montana sapphire mines was even less successful because of the very low profit margin in sapphires that are not blue. Blue sapphires are extremely rare at Montana sites other than Yogo Gulch.
Other Montana sapphires were heavily mined during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
for industrial uses. However, because the Yogo mines were still owned by the British, they were little affected by the war. Hoover remained caretaker of the mines until shortly before his death on March 11, 1954. For much of the 1930s and 1940s he was the sole employee of the mine and spent $29,000 of his own money to pay the mine's property taxes. The sixth American company to acquire the Yogo dike was the Yogo Sapphire Mining Corporation of Billings, Montana
Billings, Montana
Billings is the largest city in the U.S. state of Montana, and is the principal city of the Billings Metropolitan Area, the largest metropolitan area in over...
. The firm made its initial offer in 1946 and obtained an agreement with the English in 1949. However, legal wrangling delayed the actual purchase until July 1956. The final price was $65,000 and various stock considerations. Like so many other Yogo ventures, its capital was exhausted. The Yogo Sapphire Mining Corporation then changed its name to the same as the British firm's name: New Mine Sapphire Syndicate. It became known as the "American Syndicate" to distinguish it from the previous "English Syndicate". Production was poor and mining ceased in September 1959. From 1959–1963 the mine was "open" resulting in hobbyists, picknickers, and rockhounds from all over America and Canada coming to gather loose rough. The American Syndicate finally took action to stop this in 1963, with fences and threats of prosecution. The American Syndicate had leased the mine to several operators. One of these was Siskon, Inc. of Nevada, who lost a significant amount of money. They sued and in May 1965 the Montana Supreme Court ruled in Siskon's favor. Siskon bought the mine at a sheriff's sale and in turn leased it to a group headed by Arnold Baron, who had a background in gemcutting and jewelry. Baron organized some German and Thai gemcutters and had success in marketing Yogos in America—the first time that occurred in 50 years. However, due to the difficulty in mining the hard rock site, he did not exercise his option to buy the mine and Siskon sold it in August 1968 when Herman Yaras bought it for $585.000.
Yaras' firm was called Sapphire Village, Inc. Yaras was from Oxnard, California
Oxnard, California
Oxnard is the 113th largest city in the United States, 19th largest city in California and largest city in Ventura County, California, by way of population. It is located at the western edge of the fertile Oxnard Plain, and is an important agricultural center, with its distinction as the...
. This eventually led to what is now called Sapphire Village in early 1969, a nearby homesite development where people can gather their own sapphires through limited mining rights. "Mining" on these homesites was limited to hand tools. Meanwhile, Sapphire Village, Inc. did little to mine and market sapphires and it folded. Yaras sold the mine in 1973 to Chikara Kunisaki, an Oxnard, California native and celery farmer. Kunisaki owned one of the original homes in Sapphire Village and named his firm Sapphire International Corporation. Kunisaki then made the first serious effort to mine Yogo Gulch since the early days of the English Mine. He built a modern 3,000 foot tunnel at the site of the old American Mine that became known as the "Kunisaki Tunnel". However, Sapphire International Corporation's operations were so costly that it shut down operations in fall 1976.
Victor di Suvero and his firm Sapphire-Yogo Mines were next in January 1977 with a lease on the mine. Di Suvero was a native-born Italian who grew up in Tientsin, China and had been successful with a jade mine in California. Di Suvero's expertise was in marketing and he formed Sapphire Trading to cut and market the Yogos. He had novel marketing ideas but neglected the mining aspects of business. Consequently he was unable to make payments and this venture folded in fall 1979. At this point, only 4 Americans had been successful at Yogo Gulch and that was early in its mining history. At least thirteen American Yogo mining efforts had failed. Besides financial and hard rock mining difficulties, the Americans did not understand gem marketing. They generally approached the Yogos as if they were gold nuggets; not being able to see past a bag full of sapphire roughs.
Kunisaki then put his mine up for sale, asking $6 million to recoup his expenses. Even though mine profits had been poor over the decades, during this time prices of precious gems were very high due to the world wide oil crises of the 1970s and early 1980s. Four individuals or groups seriously considered Kunisaki's offer. Relying heavily upon the expertise of Brown, Harry C. Bullock and J. R. Edington formed the limited partnership American Yogo Sapphire Limited, the 14th American company to work the Yogo dike. They paid the $6 million price and then raised $7.2 million in funding by October 1981. Bullock and Brown had Yogo mine experience prior to this as they had worked with di Suvero. Bullock's plan included mining, cutting, making jewelry, and marketing—the whole specturm of the business. Brown discovered he could get the best gemcutters for the best price, who were also willing to improve their skills, in Thailand
Thailand
Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...
. This is where American Yogo Sapphire Limited set up its network of cutters. Brown also set up a security system that was computerized, thorough, and started at the mine and included the Thai cutters. Bigger roughs were sent to American cutters, specialty cuts were done in Germany, and a few cuts were done in Hong Kong. The vast majority of cuts were done in Thailand. American Yogo Sapphire Limited secured a $5 million line of credit with Citibank
Citibank
Citibank, a major international bank, is the consumer banking arm of financial services giant Citigroup. Citibank was founded in 1812 as the City Bank of New York, later First National City Bank of New York...
. Desiring a more modern name, American Yogo Sapphire Limited changed its name to Intergem Limited in spring 1982. Intergem marketed the Yogo as the Royal American Sapphire. Their first line of jewelry appeared in late summer 1982. Intergem started by marketing the jewelry regionally in the American west and then national marketing. They also developed a system of authorized dealers. Intergem began marketing the Yogo, rather Royal American Sapphire, as the world's only guaranteed untreated sapphire—a claim which rocked the gem trade because by 1982 the issue of heat treating gems had become a major issue in the gem trade. At that time 95% of all the world's sapphires were being heated to enhance their natural color. The Thais had taken this a step further by buying large quantities of Sri Lankan sapphires that were naturally colorless, known as geuda
Geuda
Geuda is a form of the mineral corundum, or sapphire, found primarily in Sri Lanka. Around 70%-80% gems mined in Sri Lanka belongs to Geuda varieties...
, and heating them to a totally artificial blue. Compounding the problem, heated gems often fade over time. Trained gemologists can detect a heated gem 95% of the time. Intergem's marketing of guaranteed untreated Yogos set them against many in the gem industry. This issue appeared as a front page story in the Wall Street Journal on August 29, 1984 in an article by Bill Richards entitled "Carats and Schticks: Sapphire Marketer Upsets The Gem Industry". In its first 4 years Intergem met with success. In 1984 alone sales were over $3 million. In 1985 there was a movement in Pennsylvania to require disclosure that a gem had been treated. Large numbers of gem professionals were visiting Yogo Gulch. However, problems were brewing.
Intergem had begun planning to dig even deeper into the Yogo dike; which held more known reserves than all the world's other known sapphire deposits combined; albeit deep underground than near the surface like the other known deposits. By this time Sapphire International Corporation had been renamed to Roncor; to which Intergem had made a down payment and agreed to make semi-annual payments. Intergem also had loan and interest payments to make to Citibank. Intergem's sales were steadily increasing, but even still not enough cash was coming in and in May 1985 they missed a $250,000 payment to Roncor. Their collateral with Citibank had declined because their collateral was their own inventory and the value of gems was declining. Citibank called in its loan. Intergem had over $1 million in sales lined up for the 1985 Christmas season but could only fill a tiny portion. In summer 1986 Roncor regained full ownership even though Intergem had sold carats and jewelry worth millions of dollars.
While the various companies attempted mine leasing with Roncor, two local married couples discovered a new site at Yogo Gulch in January 1984 by following a trail to an unused section of the dike that had previously been deemed unsuitable. They began mining the site and named it the "Vortex Mine". The company was named Vortex Mining. The mine shaft went 280 feet (85.3 m) down and contained two Yogo ore-bearing veins. The mine was successful for years but eventually declined and the Vortex Mine, which was now called Yogo Creek Mining, closed in 2004. The portion of the dike they had mined was an extension of the main dike. In 1992 Roncor found an 11 carat rough.
AMAX Exploration, operating as the Yogo Sapphire Project, signed a 22-month lease with Roncor in March 1993 and had some success in the middle and eastern portions of the dike but decided not to continue after the end of its lease due to the cost of underground mining, depletion of easily accessible Yogos, and the relatively small size of Yogos currently easily accessible. During this time additional dikes were found in the area and low grade rough was found in what is known as the "Eastern Flats Dike".
In 1995 Intergem's stock of gems began to reappear on the market because during its demise Intergem had paid its salesmen in sapphires. After Intergem collapsed, many of its salesmen continued to sell Yogos, especially after AMAX ceased operations. Citibank also had obtained a large stock of Yogo pieces as a result of Intergem's demise reputedly worth $3.5 million and consisting of 200,000 carats of rough, 22,000 carats of cut gems, and 2,000 pieces of jewelry. This sat in the bank's vaults until 1991 when Sofus Michelsen, director of the Center for Gemstone Evaluation and creator of the Michelsen Gemstone Index, became interested. In 1992 he and Jim Adair, a Missoula, Montana
Missoula, Montana
Missoula is a city located in western Montana and is the county seat of Missoula County. The 2010 Census put the population of Missoula at 66,788 and the population of Missoula County at 109,299. Missoula is the principal city of the Missoula Metropolitan Area...
jeweler who is the world's largest retailer of Yogos, got together and by October 1994 Adair had purchased most of Yogo material Citibank had, which had been stored in 4 sealed bags, which contained a lot of dirt. Only one of the bags was truly valuable. Adair and Michelsen designed custom cutting techniques for Yogos. Then a Canadian company called Pacific Cascade Sapphires operated a mining lease from Roncor in 2000 and 2001 but ran out of funds before becoming successful and their option expired. By this time most of the easily accessible Yogos had been mined and miners were having to dig deeper; further increasing costs.
A new owner bought Vortex in 2008 and is in operation as of late 2011. Its operations are environmentally friendly, using methods such as recycling all water and not using chemicals. As of 2011, there is also mining activity at Sapphire Village, though the Roncor mines are inactive.
State gem of Montana
The sapphire became one of Montana's two official state gemstones in 1969, 104 years from the time of discovery. Although "Sapphire" Collins recognized as early as 1865 that pebbles he found the Missouri River were of value, he could not convince bankers, merchants, or gem dealers of this since his finds were of lesser quality. It was the discovery of Yogo sapphires at Yogo Gulch in 1895 that spurred investment in sapphire mines throughout the state, mostly by influential people and firms from the eastern United States and England. In the 20th century, when designation of a state gemstone was considered, the Montana Council of Rock and Mineral Clubs supported two nominees: sapphires and Montana agateAgate
Agate is a microcrystalline variety of silica, chiefly chalcedony, characterised by its fineness of grain and brightness of color. Although agates may be found in various kinds of rock, they are classically associated with volcanic rocks and can be common in certain metamorphic rocks.-Etymology...
s. Agates were chosen due to their great abundance, particularly in the Yellowstone River
Yellowstone River
The Yellowstone River is a tributary of the Missouri River, approximately long, in the western United States. Considered the principal tributary of the upper Missouri, the river and its tributaries drain a wide area stretching from the Rocky Mountains in the vicinity of the Yellowstone National...
basin, which flows from Yellowstone National Park
Yellowstone National Park
Yellowstone National Park, established by the U.S. Congress and signed into law by President Ulysses S. Grant on March 1, 1872, is a national park located primarily in the U.S. state of Wyoming, although it also extends into Montana and Idaho...
north to Livingston
Livingston, Montana
-Geography:Livingston is located at , at an altitude of 4.501 feet .According to the United States Census Bureau, the city has a total area of , of which, of it is land and 0.38% is waters.-Climate:-Demographics:...
, then east through Montana until its confluence with the Missouri just over the state's boundary with North Dakota. Finally, in 1969, these gems were jointly declared the state gemstones.
Notable Yogo sapphires
There are a number of Yogo sapphires kept at the Smithsonian InstitutionSmithsonian Institution
The Smithsonian Institution is an educational and research institute and associated museum complex, administered and funded by the government of the United States and by funds from its endowment, contributions, and profits from its retail operations, concessions, licensing activities, and magazines...
. The first were noted in its annual report for the year ending June 30, 1899, when the Smithsonian reported that Dr. L. T. Chamberlain gave them 2 cut Yogos and 21 other sapphires, as well as other gems, for its Dr. Isaac Lea
Isaac Lea
Isaac Lea was an American conchologist, geologist, and businessman, who was born in Wilmington, Delaware.-Life:...
gem and mineral collection. In 2006, a representative of the Smithsonian Institution asked Paula Crevoshay, a jewelry designer from Albuquerque, New Mexico
Albuquerque, New Mexico
Albuquerque is the largest city in the state of New Mexico, United States. It is the county seat of Bernalillo County and is situated in the central part of the state, straddling the Rio Grande. The city population was 545,852 as of the 2010 Census and ranks as the 32nd-largest city in the U.S. As...
, if she would take a set of sapphires from Montana and create a piece of finished jewelry. The gems in question were being donated to the Smithsonian's Gem and Mineral Collection by gemologist Robert Kane of Fine Gems International in Helena, Montana
Helena, Montana
Helena is the capital city of the U.S. state of Montana and the county seat of Lewis and Clark County. The 2010 census put the population at 28,180. The local daily newspaper is the Independent Record. The Helena Brewers minor league baseball and Helena Bighorns minor league hockey team call the...
, which has the largest selection of Montana sapphires in the world. He provided 333 Montana sapphires weighing 27.97 carats along with 98.48 grams of 18K yellow gold for the project. Crevoshay felt that a butterfly motif would be excellent to represent America's natural beauty, honor her mother's love of butterflies, and display the wide range of colors found in Montana sapphires. Crevoshay named the brooch "Conchita" in honor of her mother. It is also referred to as the "Sapphire Butterfly Brooch", "Conchita Sapphire Butterfly", and the "Montana Butterfly Brooch". The brooch can also be worn as a pendant or clasp and can be beaded. Two of the sapphires used are cabochon
Cabochon
A cabochon , from the Middle French caboche , is a gemstone which has been shaped and polished as opposed to faceted. The resulting form is usually a convex top with a flat bottom. Cutting en cabochon is usually applied to opaque gems, while faceting is usually applied to transparent stones...
cut and the rest are brilliant cut. Most are from the Rock Creek deposit. The largest one, however, is a blue Yogo used for the butterfly's head. Other colors used are yellow, purple, pink, and orange. Crevoshay and Kane presented it to Smithsonian curator Jeffrey Post on May 7, 2007 in Washington, D. C.
In the earliest years of Yogo sapphire mining, before Yogos achieved their own reputation, Oriental sapphires were sold in Montana with claims they were Yogos while in Europe Yogos were sold with claims of being Oriental sapphires. However, they became notable in their own right. Paulding Farnham (1859–1927) used these stones to great advantage in several jewelry pieces he designed for the 1900 Exposition Universelle
Exposition Universelle (1900)
The Exposition Universelle of 1900 was a world's fair held in Paris, France, from April 15 to November 12, 1900, to celebrate the achievements of the past century and to accelerate development into the next...
in Paris
Paris
Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...
, where Yogo sapphires received a silver medal for color and clarity. Yogo sapphires also won a bronze medal at the 1904 Louisiana Purchase Exposition
Louisiana Purchase Exposition
The Louisiana Purchase Exposition, informally known as the Saint Louis World's Fair, was an international exposition held in St. Louis, Missouri, United States in 1904.- Background :...
in St. Louis, Missouri
St. Louis, Missouri
St. Louis is an independent city on the eastern border of Missouri, United States. With a population of 319,294, it was the 58th-largest U.S. city at the 2010 U.S. Census. The Greater St...
. The most elaborate piece of jewelry ever made with Yogos is the Tiffany Iris Brooch that was designed by Farnham and contains 120 Yogo sapphires. The Tiffany Iris Brooch was first sold on March 17, 1900 for $6,906.84. In 1923 First Lady
First Lady of the United States
First Lady of the United States is the title of the hostess of the White House. Because this position is traditionally filled by the wife of the president of the United States, the title is most often applied to the wife of a sitting president. The current first lady is Michelle Obama.-Current:The...
Florence Harding
Florence Harding
Florence Mabel Kling "Flossie" Harding , wife of President Warren G...
was given an "all Montana" ring made from a Yogo sapphire and Montana gold. In 1952 Gadsden gave cut Yogos to President Harry Truman, his wife Bess Truman
Bess Truman
Bess Truman , was the wife of Harry S. Truman and First Lady of the United States from 1945 to 1953.-Early life:...
, and their daughter Margaret Truman
Margaret Truman
Mary Margaret Truman Daniel , also known as Margaret Truman or Margaret Daniel, was an American singer who later became a successful writer. The only child of US President Harry S...
. While there is no doubt many Yogos have been sold in Europe, there is dispute about whether they are in any of the crown jewels of Europe or whether Lady Diana Spencer
Diana, Princess of Wales
Diana, Princess of Wales was the first wife of Charles, Prince of Wales, whom she married on 29 July 1981, and an international charity and fundraising figure, as well as a preeminent celebrity of the late 20th century...
's engagement ring sapphire was a Yogo. This same ring was also Kate Middleton's engagement ring. That sapphire has been reported as being 9, 12, and 18 carats.
See also
- Bismarck Sapphire NecklaceBismarck Sapphire NecklaceThe Bismarck Sapphire Necklace is a sapphire necklace designed by Cartier, Inc. in 1935. As of 2010, the necklace is on display between the Hall Sapphire and Diamond Necklace and the Logan Sapphire in the Janet Annenberg Hooker Hall of Geology, Gems, and Minerals at the Smithsonian Institution's...
- Hall Sapphire and Diamond NecklaceHall Sapphire and Diamond NecklaceThe Hall Sapphire and Diamond Necklace has 36 matched sapphires from Sri Lanka which total 195 carats. These sapphires are surrounded by 435 pear-shaped and round brilliant-cut diamonds that total 83.75 carats. The setting is platinum....
- Logan sapphireLogan sapphireThe Logan sapphire is a flawless specimen from Sri Lanka, a cushion-cut stone which possesses a rich deep blue color and is the second largest sapphire known, weighing 422.99 carats .The Logan sapphire is named after Mrs...
External links
- Biography of George F. Kunz
- Birth of a Yogo sapphire (photo sequence showing cutting of 7.73 rough to a 2.62 carat finished gem)
- Chat board post on Princess Di
- Development of Montana Sapphire Industry
- JSTOR article from Montana Magazine about Charlie Russell and Jake Hoover
- Smithsonian Gem and Mineral Collection
- Tiffany Iris Brooch image
- Tiffany Iris Brooch image