CinnabarFrom Wikipedia, the free encyclopediaJump to: navigation, search This article is about the mineral. For the plant resin, see Dragon's blood. For the moth, see Cinnabar moth.

Cinnabar

Cinnabar on Dolomite

General

Category Sulfide mineral

Chemical formula mercury(II) sulfide, HgS

Crystal symmetry Trigonal 3 2

Unit cell a = 4.145(2) Å, c = 9.496(2) Å, Z=3

Identification

ColorCochineal-red, towards brownish red and

lead-gray

Crystal habitRhombohedral to tabular. Granular to

massive and as incrustations

Crystal system Trigonal – Trapezohedral

Twinning Simple contact twins, twin plane {0001}

Cleavage Prismatic {1010}, perfect

Fracture Uneven to subconchoidal

Tenacity Slightly sectile

Mohs scale

hardness2-2.5

Luster Adamantine to dull

Streak Scarlet

Diaphaneity Transparent in thin pieces

Specific gravity 8.176

Optical properties Uniaxial (+)

Refractive index nω = 2.905 nε = 3.256

Birefringence δ = 0.351

Solubility1.04 x 10-25 g per 100 ml water (Ksp at

25°C = 2 x 10-32)[1]

References [2][3][4]

Cinnabar, or cinnabarite (red mercury(II) sulfide (Hg S ), native vermilion), is the common ore of mercury. The name comes from κινναβαρι (kinnabari), a Greek word most likely applied by Theophrastus to several distinct substances. Other sources say the word comes from the Persian شنگرف shangarf (زینجیفرح zinjifrah, a word of uncertain origin). In Latin it was sometimes known as minium, meaning also "red lead", though both of these terms now refer specifically to lead tetroxide.

Contents[hide]

1 Structure 2 Properties 3 Occurrence 4 Mining and extraction of mercury 5 Decorative use 6 Medicinal use 7 Other forms of cinnabar 8 See also 9 References 10 Other references

11 External links

[edit] StructureHgS adopts two structures, i.e. it is dimorphous.[5] The more stable form is cinnabar, which has a structure akin to that for HgO: each Hg center has two short Hg-S bonds (2.36 Å), and four longer Hg---S contacts (3.10, 3.10, 3.30, 3.30 Å). The black form of HgS has the zinc blende structure.

[edit] Properties

Cinnabar

Cinnabar is generally found in a massive, granular or earthy form and is bright scarlet to brick-red in color.[6] It occasionally occurs, however, in crystals with a non-metallic adamantine luster. Cinnabar has a rhombohedral bravais lattice, and belongs to the hexagonal crystal system, trigonal division. Its crystals grow usually in a massive habit, though they are sometimes twinned. 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 of cinnabar is 2–2.5, and its specific gravity 8.1.

Cinnabar resembles quartz in its symmetry and certain of its optical characteristics. Like quartz, it exhibits birefringence. It has the highest refractive power of any mineral. Its mean index for sodium light is 3.08,[7] whereas the index for diamond—a substance of remarkable refraction— is 2.42 and that for gallium (III) arsenide (GaAs) is 3.93.

Cinnabar mercury ore from Nevada, USA

[edit] OccurrenceGenerally cinnabar occurs as a vein-filling mineral associated with recent volcanic activity and alkaline hot springs. 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, realgar, pyrite, marcasite, opal, quartz, chalcedony, dolomite, calcite and barite.[2]

Cinnabar is found in all localities that yield mercury, notably Puerto Princesa (Philippines); Almadén (Spain); New Almaden (California); Hastings Mine and St. John's Mine, Vallejo, California;[8] Idrija (Slovenia); New Idria (California); Giza, Egypt; Landsberg, near Obermoschel in the Palatinate; Ripa, at the foot of the Apuan Alps and in the Mount Amiata (Tuscany); the mountain Avala (Serbia); Huancavelica (Peru); Murfreesboro, Arkansas; Terlingua (Texas); and the province of Guizhou in China, where fine crystals have been obtained. It was also mined near Red Devil, AK on the middle Kuskokwim River. 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 in California and Steamboat Springs, Nevada.

[edit] Mining and extraction of mercuryCinnabar has been mined since the Neolithic Age (Martín-Gil et al.). During the Roman Empire it was mined both as a pigment (Vitruvius, DA VII; IV-V) (Pliny, 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.

Since mercury is a relatively noble metal, it easily separates from its ores.

[edit] Decorative useCinnabar has been used for its color in the new world since the Olmec culture.[9] Cinnabar was often used in royal burial chambers during the peak of Mayan civilization.[10] The red stone was inserted into limestone sarcophagi, both as a decoration and, more importantly, to deter vandals and thieves with its well-known toxicity.[citation needed]

The most popularly known use of cinnabar is in Chinese carved lacquerware, a technique that apparently originated in the Song Dynasty.[11] The danger of mercury poisoning may

be reduced in ancient lacquerware by entraining the powdered pigment in lacquer,[12] 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 that approximates the appearance of pigmented lacquer.

In Ancient Rome it was the custom on festival days to color the face of the statue of Jupiter on the Capitoline Hill with cinnabar. The bodies of triumphing generals were also colored in this way, at least on some occasions.[citation needed]

[edit] Medicinal useDespite its toxicity, cinnabar has historically been used in traditional Chinese medicine, where it is called zhūshā (朱砂) and was highly valued in Chinese Alchemy where it was eponymous with the word dān (丹), which referred to alchemy, cinnabar and the elixir of immortality.

[edit] Other forms of cinnabar Hepatic cinnabar is an impure variety from the mines of Idrija in the Carniola

region of Slovenia, in which the cinnabar is mixed with bituminous and earthy matter.

Metacinnabarite is a black-colored form of HgS, which crystallizes in the cubic form.

Synthetic cinnabar is produced by treatment of Hg(II) salts with hydrogen sulfide to precipitate black, synthetic metacinnabarite, which is then heated in water. This conversion is promoted by the presence of sodium sulfide.[13]

Hypercinnabar, crystallise in the hexagonal form.

[edit] See also China red List of minerals

[edit] References1. ̂ Meyers, J.. Chem. Ed. 63: pp. 689. 1986.2. ^ a b Mineral Handbook3. ̂ Mindat4. ̂ Webmineral5. ̂ Wells, A.F. (1984). Structural Inorganic Chemistry, Oxford: Clarendon Press.

ISBN 0-19-855370-6.6. ̂ King, R. J. (2002). "Minerals explained 37: Cinnabar". Geology Today 18 (5):

195–199. doi:10.1046/j.0266-6979.2003.00366.x.

7. ̂ Schumann, Walter (1997). Gemstones of the World. New York: Sterling. ISBN 0806994614.

8. ̂ C.Michael Hogan, Marc Papineau et al., Environmental Assessment of the columbus Parkway Widening between Ascot Parkway and the Northgate Development, Vallejo, Earth Metrics Inc. Report 7853, California State Clearinghouse, Sept, 1989

9. ̂ New World's Oldest , in Time Magazine, Monday, Jul. 29, 1957 10. ̂ Cinnabar-covered ruin.11. ̂ http://www.askasia.org/teachers/images/image.php?no=65912. ̂ http://www.cst.cmich.edu/users/dietr1rv/cinnabar.htm R. V. Dietrich, 200513. ̂ Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San

Diego, 2001. ISBN 0-12-352651-5.

[edit] 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