Jade is an ornamental stone.
The term
jade is applied to two different
metamorphic rockMetamorphic 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...
s that are made up of different
silicate mineralsThe silicate minerals make up the largest and most important class of rock-forming minerals, constituting approximately 90 percent of the crust of the Earth. They are classified based on the structure of their silicate group...
:
- Nephrite
Nephrite is a variety of the calcium and magnesium-rich amphibole mineral actinolite . The chemical formula for nephrite is Ca25Si8O222. It is one of two different mineral species called jade. The other mineral species known as jade is jadeite, which is a variety of pyroxene...
consists of a microcrystaline interlocking fibrous matrix of the calcium, magnesium-iron rich amphiboleAmphibole is the name of an important group of generally dark-colored rock-forming inosilicate minerals, composed of double chain tetrahedra, linked at the vertices and generally containing ions of iron and/or magnesium in their structures.-Mineralogy:...
mineral series tremoliteTremolite is a member of the amphibole group of silicate minerals with composition: Ca2Mg5Si8O222. Tremolite forms by metamorphism of sediments rich in dolomite and quartz. Tremolite forms a series with actinolite and ferro-actinolite. Pure magnesium tremolite is creamy white, but the color grades...
(calcium-magnesium)-ferroactinolite (calcium-magnesium-iron). The middle member of this series with an intermediate composition is called actinoliteActinolite is an amphibole silicate mineral with the chemical formula .-Etymology:The name actinolite is derived from the Greek word aktis , meaning "beam" or "ray", because of the mineral's fibrous nature...
(the silky fibrous mineral form is one form of asbestosAsbestos is a set of six naturally occurring silicate minerals used commercially for their desirable physical properties. They all have in common their eponymous, asbestiform habit: long, thin fibrous crystals...
). The higher the iron content the greener the colour.
- Jadeite
Jadeite is a pyroxene mineral with composition NaAlSi2O6. It is monoclinic. It has a Mohs hardness of about 6.5 to 7.0 depending on the composition. The mineral is dense, with a specific gravity of about 3.4. Jadeite forms solid solutions with other pyroxene endmembers such as augite and diopside ,...
is a sodium- and aluminium-rich pyroxeneThe 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...
. The gem form of the mineral is a microcrystaline interlocking crystal matrix.
Etymology
The English word
jade (alternative spellings "jaid", "jadeite") is derived (via French
l'ejade and Latin
ilia) from the Spanish term
piedra de ijada (first recorded in 1565) or "loin stone", from its reputed efficacy in curing ailments of the
loinThe loins are the sides between the lower ribs and pelvis, and the lower part of the back. It is often used when describing the anatomy of humans and quadrupeds . The anatomical reference also carries over into the description of cuts of meat from some such animals, eg...
s and
kidneyThe kidneys, organs with several functions, serve essential regulatory roles in most animals, including vertebrates and some invertebrates. They are essential in the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and...
s.
Nephrite is derived from
lapis nephriticus, the Latin version of the Spanish
piedra de ijada. In some countries, jade is more commonly known as 'greenstone'.
Nephrite versus jadeite
Nephrite and jadeite were used from prehistoric periods for
hardstone carvingHardstone carving is a general term in art history and archaeology for the carving for artistic purposes of semi-precious stones, also known as gemstones, such as jade, rock crystal , agate, onyx, jasper, serpentine or carnelian, and for an object made in this way. Normally the objects are small,...
. Jadeite has about the same hardness as quartz, while nephrite is somewhat softer. Both nephrite and jadeite are
toughIn materials science and metallurgy, toughness is the ability of a material to absorb energy and plastically deform without fracturing; Material toughness is defined as the amount of energy per volume that a material can absorb before rupturing...
, but jadeite is tougher than nephrite. It was not until the 19th century that a French mineralogist determined that "jade" was in fact two different materials.
Among the earliest known jade artifacts excavated from prehistoric sites are simple ornaments with bead, button, and tubular shapes. Additionally, jade was used for
axeThe axe, or ax, is an implement that has been used for millennia to shape, split and cut wood; to harvest timber; as a weapon; and as a ceremonial or heraldic symbol...
heads, knives, and other
weaponA weapon, arm, or armament is a tool or instrument used with the aim of causing damage or harm to living beings or artificial structures or systems...
s, which can be delicately shaped. As metal-working technologies became available, the beauty of jade made it valuable for ornaments and decorative objects. Jadeite measures between 6.5 and 7.0
Mohs hardnessThe 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...
, and Nephrite between 5.5 and 6.0, so it can be worked with quartz or garnet sand, and polished with bamboo or even ground jade.
Unusual varieties
Nephrite can be found in a creamy white form (known in China as "mutton fat" jade) as well as in a variety of green colours, whereas jadeite shows more colour variations, including blue, lavender-mauve, pink, and emerald-green colours. Of the two, jadeite is rarer, documented in fewer than 12 places worldwide. Translucent emerald-green jadeite is the most prized variety, both historically and today. As "quetzal" jade, bright green jadeite from
GuatemalaGuatemala is a country in Central America bordered by Mexico to the north and west, the Pacific Ocean to the southwest, Belize to the northeast, the Caribbean to the east, and Honduras and El Salvador to the southeast...
was treasured by
MesoamericaMesoamerica is a region and culture area in the Americas, extending approximately from central Mexico to Belize, Guatemala, El Salvador, Honduras, Nicaragua, and Costa Rica, within which a number of pre-Columbian societies flourished before the Spanish colonization of the Americas in the 15th and...
n cultures, and as "kingfisher" jade, vivid green rocks from Burma became the preferred stone of post-1800 Chinese imperial scholars and rulers. Burma (
MyanmarBurma , officially the Republic of the Union of Myanmar , is a country in Southeast Asia. Burma is bordered by China on the northeast, Laos on the east, Thailand on the southeast, Bangladesh on the west, India on the northwest, the Bay of Bengal to the southwest, and the Andaman Sea on the south....
) and Guatemala are the principal sources of modern gem jadeite. In the area of
MogaungMogaung is a town in Kachin State, Myanmar. It is situated on the Mandalay-Myitkyina railway line.-External links:* Falling Rain Genomics, Inc.* Maplandia.com...
in the old
MyitkyinaMyitkyina is the capital city of Kachin State in Myanmar , located from Yangon, and from Mandalay. In Burmese it means "near the big river", and in fact "Myitkyina" lies on the west bank of the Ayeyarwady River, just below from Myit-son of its two headstreams...
District of Upper Burma (Myanmar), jadeite formed a layer in the dark-green serpentine, and has been quarried and exported for well over a hundred years. Canada provides the major share of modern lapidary nephrite. Nephrite jade was used mostly in pre-1800
ChinaChinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
as well as in
New ZealandNew Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
, the Pacific Coast and Atlantic Coasts of North America, Neolithic Europe, and Southeast Asia. In addition to Mesoamerica, jadeite was used by Neolithic Japanese and European cultures.
Prehistoric and historic China
During
NeolithicThe Neolithic Age, Era, or Period, or New Stone Age, was a period in the development of human technology, beginning about 9500 BC in some parts of the Middle East, and later in other parts of the world. It is traditionally considered as the last part of the Stone Age...
times, the key known sources of nephrite jade in China for utilitarian and ceremonial jade items were the now depleted deposits in the Ningshao area in the
Yangtze River DeltaThe Yangtze River Delta, Yangtze Delta or YRD, also called Yangzi, or Chang Jiang Delta, Rive Chang Delta Tai Lake Region or the Golden Triangle of the Yangtze, generally comprises the triangular-shaped territory of Wu-speaking Shanghai, southern Jiangsu province and northern Zhejiang province of...
(
Liangzhu cultureThe Liangzhu culture was the last Neolithic jade culture in the Yangtze River Delta of China. Its area of influence extended from around Lake Tai north to Nanjing and the Chang Jiang, east to Shanghai and the sea, and south to Hangzhou...
3400–2250 BC) and in an area of the Liaoning province and
Inner MongoliaInner Mongolia is an autonomous region of the People's Republic of China, located in the northern region of the country. Inner Mongolia shares an international border with the countries of Mongolia and the Russian Federation...
(
Hongshan cultureThe Hongshan culture was a Neolithic culture in northeastern China. Hongshan sites have been found in an area stretching from Inner Mongolia to Liaoning, and dated from about 4700 BC to 2900 BC....
4700The 5th millennium BC saw the spread of agriculture from the Near East throughout southern and central Europe.Urban cultures in Mesopotamia and Anatolia flourished, developing the wheel. Copper ornaments became more common, marking the Chalcolithic. Animal husbandry spread throughout Eurasia,...
–2200 BC). Dushan Jade was being mined as early as 6000 BC. In the Yin Ruins of the Shang Dynasty (1600 BC to 1050 BC) in Anyang, Dushan Jade ornaments were unearthed in the tomb of the Shang kings. Jade was used to create many utilitarian and ceremonial objects, from indoor decorative items to
jade burial suitA Jade burial suit is a ceremonial suit made of pieces of jade in which royal members in Han Dynasty China were buried.-Structure of a jade burial suit:...
s. Jade was considered the "imperial gem". From the earliest Chinese dynasties to the present, the jade deposits most in use were not only those of
KhotanHotan , or Hetian , also spelled Khotan, is the seat of the Hotan Prefecture in Xinjiang, China. It was previously known in Chinese as 于窴/於窴 and to 19th-century European explorers as Ilchi....
in the Western Chinese province of
XinjiangXinjiang is an autonomous region of the People's Republic of China. It is the largest Chinese administrative division and spans over 1.6 million km2...
but other parts of China as well, such as Lantian,
Shaanxi' is a province in the central part of Mainland China, and it includes portions of the Loess Plateau on the middle reaches of the Yellow River in addition to the Qinling Mountains across the southern part of this province...
. There, white and greenish nephrite jade is found in small quarries and as pebbles and boulders in the rivers flowing from the Kuen-Lun mountain range eastward into the Takla-Makan desert area. The river jade collection is concentrated in the
YarkandThe Yarkand River is a river in the Xinjiang Uyghur Autonomous Region of western China. It is one of the headstreams of the Tarim River. It is approximately 970 km in length....
, the White Jades
(Yurungkash) and Black Jade (
KarakashThe Karakash or Black Jade River, also spelled Karakax , is a river in the Xinjiang autonomous region of the People's Republic of China, which lies partially in the disputed Aksai Chin region. The river originates near Sumde on the northern slopes of the Karakoram range in the Aksai Chin region of...
) Rivers. From the
Kingdom of KhotanThe Kingdom of Khotan was an ancient Buddhist kingdom that was located on the branch of the Silk Road that ran along the southern edge of the Taklamakan Desert in the Tarim basin. -Early names:-Capital:...
, on the southern leg of the
Silk RoadThe Silk Road or Silk Route refers to a historical network of interlinking trade routes across the Afro-Eurasian landmass that connected East, South, and Western Asia with the Mediterranean and European world, as well as parts of North and East Africa...
, yearly tribute payments consisting of the most precious white jade were made to the Chinese Imperial court and there worked into
objets d'art by skilled artisans as jade had a status-value exceeding that of
goldGold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...
or
silverSilver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
. Jade became a favorite material for the crafting of Chinese scholars' objects, such as rests for calligraphy brushes, as well as the mouthpieces of some opium pipes, due to the belief that breathing through jade would bestow longevity upon smokers who used such a pipe.
Jadeite, with its bright emerald-green, pink, lavender,
orangeThe colour orange occurs between red and yellow in the visible spectrum at a wavelength of about 585–620 nm, and has a hue of 30° in HSV colour space. It is numerically halfway between red and yellow in a gamma-compressed RGB colour space, the expression of which is the RGB colour wheel. The...
and brown colours was imported from Burma to China only after about 1800. The vivid green variety became known as Feicui (翡翠) or Kingfisher (feathers) Jade. It quickly became almost as popular as nephrite and a favorite of Qing Dynasty's nouveau riche, while scholars still had strong attachment to nephrite (white jade, or Khotan), which they deem as the symbol of a nobleman.
In the history of the art of the Chinese empire, jade has had a special significance, comparable with that of gold and diamonds in the West. Jade was used for the finest objects and cult figures, and for grave furnishings for high-ranking members of the imperial family. Due to that significance and the rising middle class in China, today the finest jade when found in nuggets of “mutton fat” jade — so-named for its marbled white consistency — can fetch $3,000 an ounce, a tenfold increase from a decade ago.
Prehistoric and historic India
The
JainistJainism is an Indian religion that prescribes a path of non-violence towards all living beings. Its philosophy and practice emphasize the necessity of self-effort to move the soul towards divine consciousness and liberation. Any soul that has conquered its own inner enemies and achieved the state...
templeA derasar is a temple for followers of Jainism, except for non-murtipujak Svetambaras. Derasar is a word used in Gujarat, Kutch and parts of Rajasthan, in other parts of India, the term Jain Mandir is used for all the Jain temples. Jain idols of Tirthankaras are worshipped there...
of
KolanpakKulpakji is a Jain shrine at the village of Kolanupaka in Nalgonda district, Andhra Pradesh, India. The temple is said to be more than 2000 years old. The temple was recently renovated by employing more than 150 artisans from Rajasthan and Gujarat...
in the
Nalgonda districtNalgonda / Nallagonda District is a district in Andhra Pradesh. It has a population of 3,483,648 of which 13.32% is urban as of 2001.-Etymology:Its name is derived from two Telugu words Nalla & Konda i.e...
,
Andhra PradeshAndhra Pradesh , is one of the 28 states of India, situated on the southeastern coast of India. It is India's fourth largest state by area and fifth largest by population. Its capital and largest city by population is Hyderabad.The total GDP of Andhra Pradesh is $100 billion and is ranked third...
,
IndiaIndia , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
is home to a 5 feet (1.5 m) high
sculptureSculpture is three-dimensional artwork created by shaping or combining hard materials—typically stone such as marble—or metal, glass, or wood. Softer materials can also be used, such as clay, textiles, plastics, polymers and softer metals...
of
MahaviraMahāvīra is the name most commonly used to refer to the Indian sage Vardhamāna who established what are today considered to be the central tenets of Jainism. According to Jain tradition, he was the 24th and the last Tirthankara. In Tamil, he is referred to as Arukaṉ or Arukadevan...
that is carved entirely out of jade. It is the largest sculpture made from a single jade rock in the world. India is also noted for its craftsman tradition of using large amounts of green serpentine or
false jade obtained primarily from Afghanistan in order to fashion jewelry and ornamental items such as sword hilts and dagger handles.
Prehistoric and early historic Korea
The use of jade and other greenstone was a long-term tradition in
KoreaKorea ) is an East Asian geographic region that is currently divided into two separate sovereign states — North Korea and South Korea. Located on the Korean Peninsula, Korea is bordered by the People's Republic of China to the northwest, Russia to the northeast, and is separated from Japan to the...
(c. 850 BC – AD 668). Jade is found in small numbers of
pit-houseA pit-house is a dwelling dug into the ground which may also be layered with stone.These structures may be used as places to tell stories, dance, sing, celebrate, and store food. In archaeology, pit-houses are also termed sunken featured buildings and are found in numerous cultures around the world...
s and burials. The craft production of small
commaA comma is a type of punctuation mark . The word comes from the Greek komma , which means something cut off or a short clause.Comma may also refer to:* Comma , a type of interval in music theory...
-shaped and tubular "jades" using materials such as jade,
microclineMicrocline is an important igneous rock-forming tectosilicate mineral. It is a potassium-rich alkali feldspar. Microcline typically contains minor amounts of sodium. It is common in granite and pegmatites. Microcline forms during slow cooling of orthoclase; it is more stable at lower temperatures...
,
jasperJasper, a form of chalcedony, is an opaque, impure variety of silica, usually red, yellow, brown or green in color; and rarely blue. This mineral breaks with a smooth surface, and is used for ornamentation or as a gemstone. It can be highly polished and is used for vases, seals, and at one time for...
, etc., in southern Korea originates from the Middle
Mumun Pottery PeriodThe Mumun pottery period is an archaeological era in Korean prehistory that dates to approximately 1500-300 BC This period is named after the Korean name for undecorated or plain cooking and storage vessels that form a large part of the pottery assemblage over the entire length of the period, but...
(c. 850–550 BC). Comma-shaped jades are found on some of the gold crowns of
SillaSilla was one of the Three Kingdoms of Korea, and one of the longest sustained dynasties in...
royalty (c. AD 300/400–668) and sumptuous
eliteElite refers to an exceptional or privileged group that wields considerable power within its sphere of influence...
burials of the Korean Three Kingdoms. After the state of Silla united the Korean Peninsula in AD 668, the widespread popularisation of death rituals related to
BuddhismBuddhism is a religion and philosophy encompassing a variety of traditions, beliefs and practices, largely based on teachings attributed to Siddhartha Gautama, commonly known as the Buddha . The Buddha lived and taught in the northeastern Indian subcontinent some time between the 6th and 4th...
resulted in the decline of the use of jade in burials as prestige mortuary goods.
Māori
Nephrite jade in
New ZealandNew Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
is known as
pounamu in the
Māori languageMāori or te reo Māori , commonly te reo , is the language of the indigenous population of New Zealand, the Māori. It has the status of an official language in New Zealand...
(often called "greenstone" in
New Zealand EnglishNew Zealand English is the dialect of the English language used in New Zealand.The English language was established in New Zealand by colonists during the 19th century. It is one of "the newest native-speaker variet[ies] of the English language in existence, a variety which has developed and...
), and plays an important role in Māori culture. It is considered a
taongaA taonga in Māori culture is a treasured thing, whether tangible or intangible. Tangible examples are all sorts of heirlooms and artefacts, land, fisheries, natural resources such as geothermal springs and access to natural resources, such as riparian water rights and access to the riparian zone of...
, or treasure, and therefore protected under the
Treaty of WaitangiThe Treaty of Waitangi is a treaty first signed on 6 February 1840 by representatives of the British Crown and various Māori chiefs from the North Island of New Zealand....
, and the exploitation of it is restricted and closely monitored. It is found only in the
South IslandThe South Island is the larger of the two major islands of New Zealand, the other being the more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman Sea, to the south and east by the Pacific Ocean...
of New Zealand, known as
Te Wai Pounamu in
MāoriMāori or te reo Māori , commonly te reo , is the language of the indigenous population of New Zealand, the Māori. It has the status of an official language in New Zealand...
—"The [land of] Greenstone Water", or
Te Wahi Pounamu—"The Place of Greenstone".
Tools, weapons and ornaments were made of it; in particular
adzeAn adze is a tool used for smoothing or carving rough-cut wood in hand woodworking. Generally, the user stands astride a board or log and swings the adze downwards towards his feet, chipping off pieces of wood, moving backwards as they go and leaving a relatively smooth surface behind...
s, the '
mereThe mere is a type of short, broad-bladed club , usually made from Nephrite jade . A mere is one of the traditional, close combat, one-handed weapons of the indigenous Māori, of New Zealand. A mere could be used to split a skull open.- Form :The Mere is a spatulate, leaf shaped, form of short club...
' (short club), and the
Hei-tikiThe hei-tiki is an ornamental pendant of the Māori which is worn around the neck. Hei-tiki are usually made of pounamu which is greenstone, and are considered a taonga . They are commonly referred to as tiki, a term that actually refers to large human figures carved in wood, and, also, the small...
(neck pendant). These were believed to have their own
manaMana is an indigenous Pacific islander concept of an impersonal force or quality that resides in people, animals, and inanimate objects. The word is a cognate in many Oceanic languages, including Melanesian, Polynesian, and Micronesian....
, handed down as valuable heirlooms, and often given as gifts to seal important agreements. Nephrite
jewelleryJewellery or jewelry is a form of personal adornment, such as brooches, rings, necklaces, earrings, and bracelets.With some exceptions, such as medical alert bracelets or military dog tags, jewellery normally differs from other items of personal adornment in that it has no other purpose than to...
of Maori design is widely popular with locals and tourists, although some of the jade used for these is now imported from
British ColumbiaBritish Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
and elsewhere.
Mesoamerica
Jade was a rare and valued material in
pre-ColumbianThe pre-Columbian era incorporates all period subdivisions in the history and prehistory of the Americas before the appearance of significant European influences on the American continents, spanning the time of the original settlement in the Upper Paleolithic period to European colonization during...
MesoamericaMesoamerica is a region and culture area in the Americas, extending approximately from central Mexico to Belize, Guatemala, El Salvador, Honduras, Nicaragua, and Costa Rica, within which a number of pre-Columbian societies flourished before the Spanish colonization of the Americas in the 15th and...
. The only source from which the various
indigenousIndigenous peoples are ethnic groups that are defined as indigenous according to one of the various definitions of the term, there is no universally accepted definition but most of which carry connotations of being the "original inhabitants" of a territory....
cultureCulture is a term that has many different inter-related meanings. For example, in 1952, Alfred Kroeber and Clyde Kluckhohn compiled a list of 164 definitions of "culture" in Culture: A Critical Review of Concepts and Definitions...
s, such as the
OlmecThe Olmec were the first major Pre-Columbian civilization in Mexico. They lived in the tropical lowlands of south-central Mexico, in the modern-day states of Veracruz and Tabasco....
and
MayaThe Maya is a Mesoamerican civilization, noted for the only known fully developed written language of the pre-Columbian Americas, as well as for its art, architecture, and mathematical and astronomical systems. Initially established during the Pre-Classic period The Maya is a Mesoamerican...
, could obtain jade was located in the
Motagua RiverThe Motagua River is a long river in Guatemala. It rises in the western highlands of Guatemala where it is also called Río Grande, and runs in an easterly direction to the Gulf of Honduras. The final few kilometres of the river form part of the Guatemala/Honduras border...
valley in
GuatemalaGuatemala is a country in Central America bordered by Mexico to the north and west, the Pacific Ocean to the southwest, Belize to the northeast, the Caribbean to the east, and Honduras and El Salvador to the southeast...
. Jade was largely an
eliteElite refers to an exceptional or privileged group that wields considerable power within its sphere of influence...
good, and was usually carved in various ways, whether serving as a medium upon which hieroglyphs were inscribed, or shaped into
symbolA symbol is something which represents an idea, a physical entity or a process but is distinct from it. The purpose of a symbol is to communicate meaning. For example, a red octagon may be a symbol for "STOP". On a map, a picture of a tent might represent a campsite. Numerals are symbols for...
ic
figurineA figurine is a statuette that represents a human, deity or animal. Figurines may be realistic or iconic, depending on the skill and intention of the creator. The earliest were made of stone or clay...
s. Generally, the material was highly symbolic, and it was often employed in the performance of
ideologicalAn ideology is a set of ideas that constitutes one's goals, expectations, and actions. An ideology can be thought of as a comprehensive vision, as a way of looking at things , as in common sense and several philosophical tendencies , or a set of ideas proposed by the dominant class of a society to...
practices and
ritualA ritual is a set of actions, performed mainly for their symbolic value. It may be prescribed by a religion or by the traditions of a community. The term usually excludes actions which are arbitrarily chosen by the performers....
s.
Enhancement
Jade may be enhanced (sometimes called "stabilized"). Note that some merchants will refer to these as Grades, but it is important to bear in mind that degree of enhancement is different from colour and texture quality. In other words, Type A jadeite is not enhanced but can have poor colour and texture. There are three main methods of enhancement, sometimes referred to as the ABC Treatment System:
- Type A jadeite has not been treated in any way except surface waxing.
- Type B treatment involves exposing a promising but stained piece of jadeite to chemical bleaches and/or acids and impregnating it with a clear polymer
A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...
resinResin in the most specific use of the term is a hydrocarbon secretion of many plants, particularly coniferous trees. Resins are valued for their chemical properties and associated uses, such as the production of varnishes, adhesives, and food glazing agents; as an important source of raw materials...
. This results in a significant improvement of transparency and colour of the material. Currently, infrared spectroscopyInfrared spectroscopy is the spectroscopy that deals with the infrared region of the electromagnetic spectrum, that is light with a longer wavelength and lower frequency than visible light. It covers a range of techniques, mostly based on absorption spectroscopy. As with all spectroscopic...
is the most accurate test for the detection of polymer in jadeite.
- Type C jade has been artificially stained or dyed. The effects are somewhat uncontrollable and may result in a dull brown. In any case, translucency is usually lost.
- B+C jade is a combination of B and C: it has been both artificially dyed AND impregnated.
- Type D jade refers to a composite stone such as a doublet comprising a jade top with a plastic backing.
See also
- Costa Rican jade tradition
Jadeite is presumed one of the most precious materials of Pre-Columbian Costa Rica. It, along with other similar looking greenstones were cherished and worked for years...
- False Jade or Serpentine
- Heavenly Horse Tomb
Cheonmachong, formerly Tomb No.155, is a tumulus located in Gyeongju, South Korea. The tomb was excavated in 1973 and is believed to date probably from the fifth century but perhaps from the sixth century CE...
, a Silla royal tomb in Korea with jade artifacts.
- Jade burial suit
A Jade burial suit is a ceremonial suit made of pieces of jade in which royal members in Han Dynasty China were buried.-Structure of a jade burial suit:...
- Mumun Pottery Period
The Mumun pottery period is an archaeological era in Korean prehistory that dates to approximately 1500-300 BC This period is named after the Korean name for undecorated or plain cooking and storage vessels that form a large part of the pottery assemblage over the entire length of the period, but...
, the time in Korea when jade ornament production began
- Pounamu
Further reading
- Laufer, Berthold, 1912, Jade: A Study in Chinese Archeology & Religion, Reprint: Dover Publications, New York. 1974.
- Rawson, Jessica
Jessica Rawson, DBE, FBA is an English art historian, curator and academic administrator, specializing in Chinese art. After many years at the British Museum, she was Warden of Merton College, Oxford, from 1994 until her retirement in 2010...
, 1975, Chinese Jade Throughout the Ages, London: Albert Saifer, ISBN 0-87556-754-1
- Jadeite sources in Mesoamerica (PDF)
- Between hell and the Stone of Heaven: Observer article on Jade Mining in Burma
- Old Chinese Jades: Real or Fake?
- Book review, The Stone of Heaven: The Secret History of Imperial Green Jade by Adrian Levy and Cathy Scott-Clark
External links