Cinnabar

Cinnabar

Overview
Cinnabar or cinnabarite (s) (red mercury(II) sulfide
Mercury sulfide
Mercury sulfide, mercuric sulfide, or mercury sulfide is a chemical compound composed of the chemical elements mercury and sulfur. It is represented by the chemical formula HgS...

 (Hg
Mercury (element)
Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...

S
Sulfide
A sulfide is an anion of sulfur in its lowest oxidation state of 2-. Sulfide is also a slightly archaic term for thioethers, a common type of organosulfur compound that are well known for their bad odors.- Properties :...

), native vermilion
Vermilion
Vermilion is an opaque orangish red pigment, similar to scarlet. As a naturally occurring mineral pigment, it is known as cinnabar, and was in use around the world before the Common Era began. Most naturally produced vermilion comes from cinnabar mined in China, and vermilion is nowadays commonly...

), is the common ore
Ore
An ore is a type of rock that contains minerals with important elements including metals. The ores are extracted through mining; these are then refined to extract the valuable element....

 of mercury
Mercury (element)
Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...

.

The name comes from κινναβαρι (kinnabari), a Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

 word most likely applied by Theophrastus
Theophrastus
Theophrastus , a Greek native of Eresos in Lesbos, was the successor to Aristotle in the Peripatetic school. He came to Athens at a young age, and initially studied in Plato's school. After Plato's death he attached himself to Aristotle. Aristotle bequeathed to Theophrastus his writings, and...

 to several distinct substances. Other sources say the word comes from the Persian
Persian language
Persian is an Iranian language within the Indo-Iranian branch of the Indo-European languages. It is primarily spoken in Iran, Afghanistan, Tajikistan and countries which historically came under Persian influence...

 شنگرف shangarf (زینجیفرح zinjifrah), a word of uncertain origin (also compare, Sanskrit: sugara). In Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 it was sometimes known as minium, meaning also "red lead", though both of these terms now refer specifically to lead tetroxide.

HgS adopts two structures, i.e.
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Encyclopedia
Cinnabar or cinnabarite (s) (red mercury(II) sulfide
Mercury sulfide
Mercury sulfide, mercuric sulfide, or mercury sulfide is a chemical compound composed of the chemical elements mercury and sulfur. It is represented by the chemical formula HgS...

 (Hg
Mercury (element)
Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...

S
Sulfide
A sulfide is an anion of sulfur in its lowest oxidation state of 2-. Sulfide is also a slightly archaic term for thioethers, a common type of organosulfur compound that are well known for their bad odors.- Properties :...

), native vermilion
Vermilion
Vermilion is an opaque orangish red pigment, similar to scarlet. As a naturally occurring mineral pigment, it is known as cinnabar, and was in use around the world before the Common Era began. Most naturally produced vermilion comes from cinnabar mined in China, and vermilion is nowadays commonly...

), is the common ore
Ore
An ore is a type of rock that contains minerals with important elements including metals. The ores are extracted through mining; these are then refined to extract the valuable element....

 of mercury
Mercury (element)
Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...

.

Word origin


The name comes from κινναβαρι (kinnabari), a Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

 word most likely applied by Theophrastus
Theophrastus
Theophrastus , a Greek native of Eresos in Lesbos, was the successor to Aristotle in the Peripatetic school. He came to Athens at a young age, and initially studied in Plato's school. After Plato's death he attached himself to Aristotle. Aristotle bequeathed to Theophrastus his writings, and...

 to several distinct substances. Other sources say the word comes from the Persian
Persian language
Persian is an Iranian language within the Indo-Iranian branch of the Indo-European languages. It is primarily spoken in Iran, Afghanistan, Tajikistan and countries which historically came under Persian influence...

 شنگرف shangarf (زینجیفرح zinjifrah), a word of uncertain origin (also compare, Sanskrit: sugara). In Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 it was sometimes known as minium, meaning also "red lead", though both of these terms now refer specifically to lead tetroxide.

Structure


HgS adopts two structures, i.e. it is dimorphous
Polymorphism (materials science)
Polymorphism in materials science is the ability of a solid material to exist in more than one form or crystal structure. Polymorphism can potentially be found in any crystalline material including polymers, minerals, and metals, and is related to allotropy, which refers to chemical elements...

. The more stable form is cinnabar, which has a structure akin to that for HgO
Mercury(II) oxide
Mercury oxide, also called mercuric oxide or simply mercury oxide, has a formula of HgO. It has a red or orange color. Mercury oxide is a solid at room temperature and pressure...

: each Hg center has two short Hg-S bonds (2.36 Å
Ångström
The angstrom or ångström, is a unit of length equal to 1/10,000,000,000 of a meter . Its symbol is the Swedish letter Å....

), and four longer Hg---S contacts (3.10, 3.10, 3.30, 3.30 Å). The black form of HgS has the zincblende structure.

Properties



Cinnabar is generally found in a massive, granular or earthy form and is bright scarlet to brick-red in color. It occasionally occurs in crystals with a non-metallic adamantine luster. Cinnabar has a rhombohedral bravais lattice, and belongs to the hexagonal crystal system
Hexagonal crystal system
In crystallography, the hexagonal crystal system is one of the 7 crystal systems, the hexagonal lattice system is one of the 7 lattice systems, and the hexagonal crystal family is one of the 6 crystal families...

, trigonal division. Its crystals grow usually in a massive habit, though they are sometimes twinned
Crystal twinning
Crystal twinning occurs when two separate crystals share some of the same crystal lattice points in a symmetrical manner. The result is an intergrowth of two separate crystals in a variety of specific configurations. A twin boundary or composition surface separates the two crystals....

. The twinning in cinnabar is distinctive and forms a penetration twin that is ridged with six ridges surrounding the point of a pyramid. It could be thought of as two scalahedral crystals grown together with one crystal going the opposite way of the other crystal. The 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...

 of cinnabar is 2–2.5, and its specific gravity
Specific gravity
Specific gravity is the ratio of the density of a substance to the density of a reference substance. Apparent specific gravity is the ratio of the weight of a volume of the substance to the weight of an equal volume of the reference substance. The reference substance is nearly always water for...

 8.1.

Cinnabar resembles quartz
Quartz
Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...

 in its symmetry and certain of its optical characteristics. Like quartz, it exhibits birefringence
Birefringence
Birefringence, or double refraction, is the decomposition of a ray of light into two rays when it passes through certain anisotropic materials, such as crystals of calcite or boron nitride. The effect was first described by the Danish scientist Rasmus Bartholin in 1669, who saw it in calcite...

. It has the highest refractive
Refraction
Refraction is the change in direction of a wave due to a change in its speed. It is essentially a surface phenomenon . The phenomenon is mainly in governance to the law of conservation of energy. The proper explanation would be that due to change of medium, the phase velocity of the wave is changed...

 power of any mineral
Mineral
A mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...

. Its mean index
Refractive index
In optics the refractive index or index of refraction of a substance or medium is a measure of the speed of light in that medium. It is expressed as a ratio of the speed of light in vacuum relative to that in the considered medium....

 for sodium
Sodium
Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...

 light is 3.08, whereas the index for diamond is 2.42 and that for gallium (III) arsenide (GaAs) is 3.93.

Occurrence


Generally cinnabar occurs as a vein-filling mineral
Mineral
A mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...

 associated with recent volcanic activity
Volcanism
Volcanism is the phenomenon connected with volcanoes and volcanic activity. It includes all phenomena resulting from and causing magma within the crust or mantle of a planet to rise through the crust and form volcanic rocks on the surface....

 and alkaline hot spring
Hot spring
A hot spring is a spring that is produced by the emergence of geothermally heated groundwater from the Earth's crust. There are geothermal hot springs in many locations all over the crust of the earth.-Definitions:...

s. Cinnabar is deposited by epithermal ascending aqueous solutions (those near surface and not too hot) far removed from their igneous source.

It is associated with native mercury, stibnite
Stibnite
Stibnite, sometimes called antimonite, is a sulfide mineral with the formula Sb2S3. This soft grey material crystallizes in an orthorhombic space group. It is the most important source for the metalloid antimony...

, realgar
Realgar
Realgar, α-As4S4, is an arsenic sulfide mineral, also known as "ruby sulphur" or "ruby of arsenic". It is a soft, sectile mineral occurring in monoclinic crystals, or in granular, compact, or powdery form, often in association with the related mineral, orpiment . It is orange-red in colour, melts...

, pyrite
Pyrite
The mineral pyrite, or iron pyrite, is an iron sulfide with the formula FeS2. This mineral's metallic luster and pale-to-normal, brass-yellow hue have earned it the nickname fool's gold because of its resemblance to gold...

, marcasite
Marcasite
The mineral marcasite, sometimes called white iron pyrite, is iron sulfide with orthorhombic crystal structure. It is physically and crystallographically distinct from pyrite, which is iron sulfide with cubic crystal structure. Both structures do have in common that they contain the disulfide...

, opal
Opal
Opal is an amorphous form of silica related to quartz, a mineraloid form, not a mineral. 3% to 21% of the total weight is water, but the content is usually between 6% to 10%. It is deposited at a relatively low temperature and may occur in the fissures of almost any kind of rock, being most...

, quartz
Quartz
Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...

, chalcedony
Chalcedony
Chalcedony is a cryptocrystalline form of silica, composed of very fine intergrowths of the minerals quartz and moganite. These are both silica minerals, but they differ in that quartz has a trigonal crystal structure, while moganite is monoclinic...

, dolomite
Dolomite
Dolomite is a carbonate mineral composed of calcium magnesium carbonate CaMg2. The term is also used to describe the sedimentary carbonate rock dolostone....

, calcite
Calcite
Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate . The other polymorphs are the minerals aragonite and vaterite. Aragonite will change to calcite at 380-470°C, and vaterite is even less stable.-Properties:...

 and barite
Barite
Baryte, or barite, is a mineral consisting of barium sulfate. The baryte group consists of baryte, celestine, anglesite and anhydrite. Baryte itself is generally white or colorless, and is the main source of barium...

.

Cinnabar is found in all localities that yield mercury, notably Puerto Princesa (Philippines
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...

); Almadén
Almadén
Almadén, Spain, is a town and municipality in the province of Ciudad Real, within the autonomous community of Castile-La Mancha. The town is located at 4° 49' W and 38° 46' N and is 589 meters above sea level. Almadén is approximately 200 km south of Madrid in the Sierra Morena...

 (Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...

); New Almaden
New Almaden
The New Almaden quicksilver mine in the Santa Teresa Hills in Santa Clara County, California, United States, is the oldest and most productive quicksilver mine in the U.S. The site was known to the Ohlone Indians for its cinnabar long before a Mexican settler discovered the ores in 1820...

 (California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

); Hastings Mine
Hastings Mine
The Hastings Mine is a mineral extraction site approximately northeast of the city of Vallejo, Solano County, California. The Hastings site on Sulfur Springs Mountain was used for extraction of cinnabar until the year 1930. The Hastings Mine is classified as a medium priority mine from the...

 and St. John's Mine
St. John's Mine
The St John's Mine is a mineral extraction site approximately three miles north of the city of Vallejo in Solano County, California, United States. The St John's site was used for extraction of cinnabar in the early 1900s. The St. John's Mine is classified as a medium priority mine from the...

, Vallejo, California
Vallejo, California
Vallejo is the largest city in Solano County, California, United States. The population was 115,942 at the 2010 census. It is located in the San Francisco Bay Area on the northeastern shore of San Pablo Bay...

; Idrija
Idrija
Idrija is a small town and municipality in the Goriška region of Slovenia. It is known for its mercury mine and lace....

 (Slovenia
Slovenia
Slovenia , officially the Republic of Slovenia , is a country in Central and Southeastern Europe touching the Alps and bordering the Mediterranean. Slovenia borders Italy to the west, Croatia to the south and east, Hungary to the northeast, and Austria to the north, and also has a small portion of...

); New Idria
New Idria, California
New Idria was an unincorporated town in San Benito County, California. It is named after a now-inoperative quicksilver mine of the same name. The mine itself was named in honor of the world's second largest quicksilver mine in Idrija, Slovenia The town grew to support the mining operations, but...

 (California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

); Giza, Egypt; Landsberg, near Obermoschel
Obermoschel
Obermoschel is a town in the district Donnersbergkreis, in Rhineland-Palatinate, Germany. It is part of the Verbandsgemeinde Alsenz-Obermoschel. It is situated 15 km southwest of Bad Kreuznach....

 in the Palatinate
Rhineland-Palatinate
Rhineland-Palatinate is one of the 16 states of the Federal Republic of Germany. It has an area of and about four million inhabitants. The capital is Mainz. English speakers also commonly refer to the state by its German name, Rheinland-Pfalz ....

; Ripa
Ripa
Ripa is a Latin word, meaning the bank of a river. The word is part of the name of a number of places, mainly in Italy.Ripa may refer to:-People:*Albert de Rippe , Italian lutenist and composer, also known as Alberto da Ripa...

, at the foot of the Apuan Alps and in the Mount Amiata (Tuscany
Tuscany
Tuscany is a region in Italy. It has an area of about 23,000 square kilometres and a population of about 3.75 million inhabitants. The regional capital is Florence ....

); the mountain Avala (Serbia); Huancavelica
Huancavelica
Huancavelica is a city in Peru. It is the capital of the Huancavelica region and has a population of approximately 40,000. Indigenous peoples represent a major percentage of the population. It has an approximate altitude of 3,600 meters; the climate is cold and dry between the months of February...

 (Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....

); Murfreesboro, Arkansas
Murfreesboro, Arkansas
Murfreesboro is a city in Pike County, Arkansas, United States. The population was 1,764 at the 2000 census. The city is the county seat of Pike County....

; Terlingua
Terlingua, Texas
Terlingua is a mining district in southwestern Brewster County, Texas, United States. It is located near the Rio Grande and the Texas villages of Lajitas and Study Butte, Texas,as well as the Mexican village of Santa Elena. The discovery of cinnabar, from which the metal mercury is extracted, in...

 (Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

); and the province of Guizhou
Guizhou
' is a province of the People's Republic of China located in the southwestern part of the country. Its provincial capital city is Guiyang.- History :...

 in China
China
Chinese 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...

, where fine crystals have been obtained. It was also mined near Red Devil, Alaska
Red Devil, Alaska
Red Devil is a census-designated place in Bethel Census Area, Alaska, United States. The population was 48 at the 2000 census.-Geography:Red Devil is located at ....

 on the middle Kuskokwim River
Kuskokwim River
The Kuskokwim River or Kusko River is a river, long, in Southwest Alaska in the United States. It is the ninth largest river in the United States by average discharge volume at its mouth and seventeenth largest by basin drainage area.The river provides the principal drainage for an area of the...

. Red Devil was named after the Red Devil cinnabar mine, a primary source of mercury.

Cinnabar is still being deposited at the present day from the hot waters of Sulphur Bank Mine
Sulphur Bank Mine
The Sulphur Bank Mine is located near Clearlake Oaks and Clear Lake in Lake County, California. The mine became one of the most noted mercury producers in the world....

 in California and Steamboat Springs, Nevada
Steamboat Springs, Nevada
Steamboat Springs is a small volcanic field of rhyolitic lava domes and flows in western Nevada, USA, located south of Reno. There is extensive geothermal activity in the area, including numerous hot springs, steam vents, and fumaroles...

.

Mining and extraction of mercury


Cinnabar has been mined since the Neolithic Age (Martín-Gil et al.). During the Roman Empire
Roman Empire
The Roman Empire was the post-Republican period of the ancient Roman civilization, characterised by an autocratic form of government and large territorial holdings in Europe and around the Mediterranean....

 it was mined both as a pigment (Vitruvius
Vitruvius
Marcus Vitruvius Pollio was a Roman writer, architect and engineer, active in the 1st century BC. He is best known as the author of the multi-volume work De Architectura ....

, DA
De architectura
' is a treatise on architecture written by the Roman architect Vitruvius and dedicated to his patron, the emperor Caesar Augustus, as a guide for building projects...

 VII; IV-V) (Pliny
Pliny the Elder
Gaius Plinius Secundus , better known as Pliny the Elder, was a Roman author, naturalist, and natural philosopher, as well as naval and army commander of the early Roman Empire, and personal friend of the emperor Vespasian...

, HN; XXXIII, XXXVI-XLII) and for its mercury content (Pliny HN; XXXIII, XLI), and it has been the main source of mercury throughout the centuries.

To produce liquid (quicksilver) mercury, crushed cinnabar ore is roasted in rotary furnaces. Pure mercury separates from sulfur in this process and easily evaporates. A condensing column is used to collect the liquid metal, which is most often shipped in iron flasks.

Toxicity



Because of its mercury content, cinnabar can be toxic to human beings. Though ancient peoples in South America often used cinnabar for art, or processed it into refined mercury (as a means to gild silver and gold to objects) "the toxic properties of mercury were well known. It was dangerous to those who mined and processed cinnabar, it caused shaking, loss of sense, and death...data suggest that mercury was retorted from cinnabar and the workers were exposed to the toxic mercury fumes." Overexposure to mercury, mercurialism, was seen as an occupational disease to the ancient Romans, "Mining in the Spanish cinnabar mines of Almaden, 225 km southwest of Madrid, was regarded as being akin to a death sentence due to the shortened life expectancy of the miners, who were slaves or convicts."

Cinnabar turned into a fine powder is often referred to as vermilion
Vermilion
Vermilion is an opaque orangish red pigment, similar to scarlet. As a naturally occurring mineral pigment, it is known as cinnabar, and was in use around the world before the Common Era began. Most naturally produced vermilion comes from cinnabar mined in China, and vermilion is nowadays commonly...

 which can be used as a food coloring in extremely small amounts. Animal testing has shown vermilion "proved fatal to animals in the proportion of from thirty to seventy grains, even when applied externally to a wound."

Decorative use


Cinnabar has been used for its color in the new world since the Olmec
Olmec
The 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....

 culture. Cinnabar was often used in royal
Maya rulers
Mayan kings were the centers of power for Mayan civilization. Each Mayan city-state was controlled by a dynasty of kings, who collectively drove the empire forward.-Symbols of power:...

 burial chambers
Maya death rituals
Maya death rituals were an important part of their religion.The Maya are thought of as religious people, who lived in fear of the destructive nature of their gods. Death rituals became an important part of their religion; they developed many traditions to commemorate the recently deceased and...

 during the peak of Mayan civilization.

The most popularly known use of cinnabar is in Chinese carved lacquerware
Lacquerware
Lacquerware are objects decoratively covered with lacquer. The lacquer is sometimes inlaid or carved. Lacquerware includes boxes, tableware, buttons and even coffins painted with lacquer in cultures mostly in the Eastern Hemisphere.-History:...

, a technique that apparently originated in the Song Dynasty
Song Dynasty
The Song Dynasty was a ruling dynasty in China between 960 and 1279; it succeeded the Five Dynasties and Ten Kingdoms Period, and was followed by the Yuan Dynasty. It was the first government in world history to issue banknotes or paper money, and the first Chinese government to establish a...

. The danger of mercury poisoning may be reduced in ancient lacquerware by entraining
Entrainment (engineering)
Entrainment as commonly used in various branches of engineering may be defined as the entrapment of one substance by another substance. For example:* The entrapment of liquid droplets or solid particulates in a flowing gas, as with smoke....

 the powdered pigment in lacquer
Lacquer
In a general sense, lacquer is a somewhat imprecise term for a clear or coloured varnish that dries by solvent evaporation and often a curing process as well that produces a hard, durable finish, in any sheen level from ultra matte to high gloss and that can be further polished as required...

, but could still pose an environmental hazard if the pieces were accidentally destroyed. In the modern jewelry industry, the toxic pigment is replaced by a resin-based polymer
Polymer
A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...

 that approximates the appearance of pigmented lacquer.

Other forms of cinnabar

  • Hepatic cinnabar is an impure variety from the mines of Idrija
    Idrija
    Idrija is a small town and municipality in the Goriška region of Slovenia. It is known for its mercury mine and lace....

     in the Carniola
    Carniola
    Carniola was a historical region that comprised parts of what is now Slovenia. As part of Austria-Hungary, the region was a crown land officially known as the Duchy of Carniola until 1918. In 1849, the region was subdivided into Upper Carniola, Lower Carniola, and Inner Carniola...

     region of Slovenia
    Slovenia
    Slovenia , officially the Republic of Slovenia , is a country in Central and Southeastern Europe touching the Alps and bordering the Mediterranean. Slovenia borders Italy to the west, Croatia to the south and east, Hungary to the northeast, and Austria to the north, and also has a small portion of...

    , in which the cinnabar is mixed with bituminous and earthy matter.
  • Metacinnabarite is a black-colored form of HgS, which crystallizes in the cubic
    Cubic crystal system
    In crystallography, the cubic crystal system is a crystal system where the unit cell is in the shape of a cube. This is one of the most common and simplest shapes found in crystals and minerals....

     form.
  • Synthetic cinnabar is produced by treatment of Hg(II) salts with hydrogen sulfide
    Hydrogen sulfide
    Hydrogen sulfide is the chemical compound with the formula . It is a colorless, very poisonous, flammable gas with the characteristic foul odor of expired eggs perceptible at concentrations as low as 0.00047 parts per million...

     to precipitate
    Precipitation (chemistry)
    Precipitation is the formation of a solid in a solution or inside anothersolid during a chemical reaction or by diffusion in a solid. When the reaction occurs in a liquid, the solid formed is called the precipitate, or when compacted by a centrifuge, a pellet. The liquid remaining above the solid...

     black, synthetic metacinnabarite, which is then heated in water. This conversion is promoted by the presence of sodium sulfide
    Sodium sulfide
    Sodium sulfide is the name used to refer to the chemical compound Na2S, but more commonly it refers to the hydrate Na2S·9H2O. Both are colorless water-soluble salts that give strongly alkaline solutions...

    .
  • Hypercinnabar, crystallise in the hexagonal
    Hexagonal crystal system
    In crystallography, the hexagonal crystal system is one of the 7 crystal systems, the hexagonal lattice system is one of the 7 lattice systems, and the hexagonal crystal family is one of the 6 crystal families...

     form.

See also



Other references

  • Martín-Gil, J; Martín-Gil, FJ; Delibes-de-Castro, G; Zapatero-Magdaleno, P; Sarabia-Herrero, FJ (1995). The first use of vermillion. Cellular and Molecular Life Sciences, 51(8):759-761

External links