Cinnabar (; ), or cinnabarite (), also known as mercurblende is the bright scarlet to brick-red form of Mercury sulfide (HgS). It is the most common source ore for refining elemental mercury and is the historic source for the brilliant red or scarlet pigment termed vermilion and associated red mercury pigments.
Cinnabar generally occurs as a vein-filling mineral associated with volcanic activity and alkaline . The mineral resembles quartz in symmetry and it exhibits birefringence. Cinnabar has a mean refractive index near 3.2, a hardness between 2.0 and 2.5, and a specific gravity of approximately 8.1. The color and properties derive from a structure that is a hexagonal crystalline bravais lattice belonging to the trigonal crystal system, crystals that sometimes exhibit Crystal twinning.
Cinnabar has been used for its color since antiquity in the Near East, including as a rouge-type cosmetics, in the New World since the Olmec culture, and in China since as early as the Yangshao culture, where it was used in coloring stoneware. In Roman times, cinnabar was highly valued as paint for walls, especially interiors, since it darkened when used outdoors due to exposure to sunlight.
Associated modern precautions for the use and handling of cinnabar arise from the mercury toxicity, which was recognized as early as ancient Rome.
Mercury(II) sulfide, HgS, adopts the cinnabar structure described, and one additional structure, i.e. it is dimorphous. Cinnabar is the more stable form, and is a structure akin to that of HgO: each Hg center has two short Hg−S bonds (each 2.36 angstrom), and four longer contacts (with 3.10, 3.10, 3.30 and 3.30 Å separations). In addition, HgS is found in a black, non-cinnabar polymorph (metacinnabar) that has the zincblende structure.
Cinnabar is found in essentially all mineral extraction localities that yield mercury, notably Almadén (Spain). This mine was exploited from Roman times until 1991, being for centuries the most important cinnabar deposit in the world. Good cinnabar crystals have also been found there. Cinnabar deposits appear in Giza (Egypt); Puerto Princesa (Philippines); Red Devil, Alaska; Murfreesboro, Arkansas; New Almaden Mine in San Jose, California; New Idria, California, the Hastings Mine and St. John's Mine both in Vallejo, California; Terlingua, Texas (United States); Idrija (Slovenia); near Obermoschel in the Palatinate; the La Ripa and Levigliani mines at the foot of the Apuan Alps and in Mount Amiata (Tuscany, Italy); Avala (Serbia); Huancavelica (Peru); the province of Guizhou in China and Western ghats in India where fine crystals have been obtained. It has been found in Dominica near its sulfur springs at the southern end of the island along the west coast.
Cinnabar is still being deposited, such as from the hot waters of Sulphur Bank Mine in California and Steamboat Springs, Nevada (United States).
To produce liquid mercury (quicksilver), crushed cinnabar ore is roasted in . 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.
Cinnabar's use as a color in the New World, since the Olmec culture, is exemplified by its use in royal burial chambers during the peak of Maya civilization, most dramatically in the 7th-century tomb of the Red Queen in Palenque, where the remains of a noble woman and objects belonging to her in her sarcophagus were completely covered with bright red powder made from cinnabar.
The most popularly known use of cinnabar is in Chinese carved lacquerware, a technique that apparently originated in the Song dynasty.
Two female mummies dated AD 1399 to 1475 found in Cerro Esmeralda in Chile in 1976 had clothes colored with cinnabar.
Occurrence
Mining and extraction of mercury
Toxicity
Decorative use
Other forms
See also
Further reading
External links
See also
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