Cinnabar has been used for its color since antiquity in the Near East, including as a rouge-type cosmetic, 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.
The name comes from Greekκιννάβαρι[7] (kinnabari),[8][9] a Greek word most likely applied by Theophrastus to several distinct substances.[7] In Latin, it was sometimes known as minium, meaning also "red cinnamon",[10] though both of these terms now refer specifically to lead tetroxide.[11]
Properties and structure
Properties
Cinnabar is generally found in a massive, granular, or earthy form and is bright scarlet to brick-red in color, though it occasionally occurs in crystals with a nonmetallic adamantine luster.[12][13] It resembles quartz in its symmetry. It exhibits birefringence, and it has the second-highest refractive index of any mineral.[14] Its mean refractive index is 3.08 (sodium light wavelengths),[15] versus the indices for diamond and the non-mineral gallium(III) arsenide (GaAs), which are 2.42 and 3.93, respectively. The hardness of cinnabar is 2.0–2.5 on the Mohs scale, and its specific gravity 8.1.[6]
Structure
Structurally, cinnabar belongs to the trigonal crystal system.[6] It occurs as thick tabular or slender prismatic crystals or as granular to massive incrustations.[4]Crystal twinning occurs as simple contact twins.[5]
Mercury(II) sulfide, HgS, adopts the cinnabar structure described, and one additional structure, i.e. it is dimorphous.[16] 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 Å), and four longer Hg···S 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.[5]
As the most common source of mercury in nature,[26] cinnabar has been mined for thousands of years, even as far back as the Neolithic Age.[27] During the Roman Empire it was mined both as a pigment,[28][29] and for its mercury content.[29]: XLI
To produce liquid mercury (quicksilver), 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.[30]
Associated modern precautions for use and handling of cinnabar arise from the toxicity of the mercury component, which was recognized as early as in ancient Rome.[31] Because of its mercury content, cinnabar can be toxic to human beings. Overexposure to mercury, mercury poisoning (mercurialism), was seen as an occupational disease to the ancient Romans. Though people in ancient 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 suggests that mercury was retorted from cinnabar and the workers were exposed to the toxic mercury fumes.[32] "Mining in the Spanish cinnabar mines of Almadén, 225 km (140 mi) 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."[33]
Cinnabar's use as a color in the New World, since the Olmec culture,[34] 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.[35]
The most popularly known use of cinnabar is in Chinese carved lacquerware, a technique that apparently originated in the Song dynasty.[36] The danger of mercury poisoning may be reduced in ancient lacquerware by entraining the powdered pigment in lacquer,[37][page needed] but could still pose an environmental hazard if the pieces were accidentally destroyed. In the modern jewellery industry, the toxic pigment is replaced by a resin-based polymer that approximates the appearance of pigmented lacquer.[citation needed]
Two female mummies dated AD 1399 to 1475 found in Cerro Esmeralda in Chile in 1976 had clothes colored with cinnabar.[38]
Other forms
Hepatic cinnabar, or paragite, is an impure brownish variety[39] from the mines of Idrija in the Carniola region of Slovenia, in which the cinnabar is mixed with bituminous and earthy matter.[40]
^Myers, R. J. (1986). "The new low value for the second dissociation constant of H2S. Its history, its best value, and its impact on teaching sulfide equilibria". Journal of Chemical Education. 63: 689.
^Calvo, Miguel (2003). Minerales y Minas de España. Vol. II. Sulfuros y sulfosales. Vitoria, Spain: Museo de Ciencias Naturales de Alava. pp. 355–359. ISBN84-7821-543-3.
^Martín Gil, J.; Martín Gil, F. J.; Delibes de Castro, G.; Zapatero Magdaleno, P.; Sarabia Herrero, F. J. (1995). "The first known use of vermillion". Experientia. 51 (8): 759–761. doi:10.1007/BF01922425. ISSN0014-4754. PMID7649232. S2CID21900879.
^Healy, Paul F.; Blainey, Marc G. (2011). "Ancient Maya mosaic mirrors: Function, symbolism, and meaning". Ancient Mesoamerica. 22 (2): 230. doi:10.1017/S0956536111000241. S2CID162282151.
^Holleman, A. F.; Wiberg, E. (2001). Inorganic Chemistry. San Diego, California: Academic Press. ISBN0-12-352651-5.
Further reading
Stewart, Susan (2014). "'Gleaming and deadly white': Toxic cosmetics in the Roman world". In Wexler, Philip (ed.). History of Toxicology and Environmental Health: Toxicology in Antiquity. Vol. II. New York, NY: Academic Press. p. 84. ISBN978-0-12-801634-3.
Barone, G.; Di Bella, M.; Mastelloni, M. A.; Mazzoleni, P.; Quartieri, S.; Raneri, S.; Sabatino, G.; Vailati, C. (2016). Pottery Production of the Pittore di Lipari: Chemical and Mineralogical Analysis of the Pigments. Minerals, Fluids and Rocks: Alphabet and Words of Planet Earth. Rimini: 2nd European Mineralogical Conference (EMC2016) 11–15 Sep 2016. p. 716.