Cinnabar


Cinnabar
Cinnabar

Cinnabar on Dolomite
General
Category Sulfide mineral
Chemical formula mercury(II) sulfide, HgS
Strunz classification 02.CD.15a
Crystal symmetry Trigonal Trapezohedral
H-M symbol: 3 2
Space group: P31 2 1
Unit cell a = 4.145(2) Å, c = 9.496(2) Å, Z=3
Identification
Color Cochineal-red, towards brownish red and lead-gray
Crystal habit Rhombohedral to tabular; granular to massive and as incrustations
Crystal system Trigonal
Twinning Simple contact twins, twin plane {0001}
Cleavage Prismatic {1010}, perfect
Fracture Uneven to subconchoidal
Tenacity Slightly sectile
Mohs scale hardness 2-2.5
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
Solubility 1.04 x 10-25 g per 100 ml water (Ksp at 25°C = 2 x 10-32)[1]
References [2][3][4]

Cinnabar (pronounced /ˈsɪnəbɑr/) or cinnabarite (/sɪnəˈbɑrt/) (red mercury(II) sulfide (HgS), native vermilion), is the common ore of mercury.

Contents

Word origin

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 (also compare, Sanskrit: sugara). In Latin 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.[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 zincblende structure.

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 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 is 2.42 and that for gallium (III) arsenide (GaAs) is 3.93.

Cinnabar mercury ore from Nevada, USA

Occurrence

Generally 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, Alaska 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.

Mining and extraction of mercury

Cinnabar 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.

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."[9] 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."[10]

Cinnabar turned into a fine powder is often referred to as vermilion 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."[11]

Decorative use

Cinnabar has been used for its color in the new world since the Olmec culture.[12] Cinnabar was often used in royal burial chambers during the peak of Mayan civilization.[13]

The most popularly known use of cinnabar is in Chinese carved lacquerware, a technique that apparently originated in the Song Dynasty. The danger of mercury poisoning may be reduced in ancient lacquerware by entraining the powdered pigment in lacquer,[14] 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.

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.[15]
  • Hypercinnabar, crystallise in the hexagonal form.

See also

DirkvdM rocks.jpg Earth sciences portal

References

  1. ^ Meyers, J. (1986). Chem. Ed. 63: pp. 689. 
  2. ^ a b Mineral Handbook
  3. ^ Mindat
  4. ^ Webmineral
  5. ^ 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. ^ Georg Petersen G. (2010). Mining and metallurgy in ancient Perú. The Geological Society of America. 
  10. ^ Andrew Wallace Hayes (2008). Principles and methods of toxicology. New York, NY: Informa Healthcare USA, Inc.. 
  11. ^ Alfred Swaine Taylor (1849). Medical jurisprudence. London, England: Wilson and Ogilvy. 
  12. ^ New World's Oldest, in Time Magazine, Monday, Jul. 29, 1957
  13. ^ Cinnabar-covered ruin.
  14. ^ http://www.cst.cmich.edu/users/dietr1rv/cinnabar.htm R. V. Dietrich, 2005
  15. ^ Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.

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


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Synonyms:

Look at other dictionaries:

  • Cinnabar — Cin na*bar, n. [L. cinnabaris, Gr. ?; prob. of Oriental origin; cf. Per. qinb[=a]r, Hind. shangarf.] [1913 Webster] 1. (Min.) Red sulphide of mercury, occurring in brilliant red crystals, and also in red or brown amorphous masses. It is used in… …   The Collaborative International Dictionary of English

  • cinnabar — ► NOUN 1) a bright red mineral consisting of mercury sulphide. 2) (also cinnabar moth) a day flying moth with black and red wings. ORIGIN Greek kinnabari …   English terms dictionary

  • cinnabar — [sin′ə bär΄] n. [ME cinabare < L cinnabaris < Gr kinnabari < ? Ar zinjafr < Pers šangarf, red lead, cinnabar] 1. mercuric sulfide, HgS, a heavy, bright red mineral, the principal ore of mercury 2. artificial mercuric sulfide, used as… …   English World dictionary

  • cinnabar — cinnabar. Mутация, фенотипически проявляющаяся в изменении цвета глаз у дрозофилы, одна из первых (наряду с vermilion <cм.>) мутаций, с помощью которой было показано биохимическое действие генов она нарушает функционирование фермента,… …   Молекулярная биология и генетика. Толковый словарь.

  • Cinnabar — Cinnabar, also known as *minium, was employed to produce the reds and vermilion used by MS illuminators. Large quantities have been mined in Spain for two millennia; it is known to chemists as mercury sulphide (HgS). Cf. Brasil; Lapis lazuli …   Dictionary of Medieval Terms and Phrases

  • cinnabar — (n.) mid 15c., red or crystalline form of mercuric sulphide, also applied to other ores of mercury, originally with reference to its use as a pigment; from O.Fr. cinabre (13c.), from L.L. cinnabaris, from Gk. kinnabari, of oriental origin (Cf.… …   Etymology dictionary

  • cinnabar or cn — — мутация, фенотипически проявляющаяся в изменении цвета глаз у дрозофилы. Это одна из первых мутаций (наряду с мутацией vermillion), с помощью которой было показано биохимическое действие генов: она нарушает функционирование фермента,… …   Генетика. Энциклопедический словарь

  • cinnabar — cinnabarine /sin euh beuh reen , beuhr in, bahr uyn, een/, cinnabaric /sin euh bar ik/, adj. /sin euh bahr /, n. 1. a mineral, mercuric sulfide, HgS, occurring in red crystals or masses: the principal ore of mercury. 2. red mercuric sulfide, used …   Universalium

  • cinnabar — gyvsidabrio(II) sulfidas statusas T sritis chemija formulė HgS atitikmenys: angl. artificial cinnabar; black mercury sulfide; cinnabar; mercuric sulfide; mercury(II) sulfide; metacinnabarite; vermilion rus. ртути(II) сульфид; ртуть сернистая …   Chemijos terminų aiškinamasis žodynas

  • cinnabar — noun Etymology: Middle English cynabare, from Anglo French & Latin; Anglo French sinopre, from Latin cinnabaris, from Greek kinnabari, of non Indo European origin; akin to Arabic zinjafr cinnabar Date: 14th century 1. artificial red mercuric… …   New Collegiate Dictionary


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