Cinnabar

It's advisable to handle cinnabar carefully to avoid generating dust and wash hands thoroughly afterward. When cutting or polishing cinnabar, wear a dust mask to prevent inhaling heavy metal particles. Store cinnabar in a sealed container in a well-ventilated area, away from children and pets. For those involved in crystal healing, never put it in your mouth.

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. It resembles quartz in its symmetry. It exhibits birefringence, and it has the second highest refractive index of any mineral. Its mean refractive index is 3.08 (sodium light wavelengths), 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.

Cinnabar generally 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. Cinnabar is essentially found in 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 also appear in Giza (Egypt); Puerto Princesa (Philippines); New Almaden (California); Hastings Mine and St. John's Mine, Vallejo, California (United States); Idrija (Slovenia); New Idria, California (United States); Moschellandsberg [de] near Obermoschel in the Palatinate; La Ripa, at the foot of the Apuan Alps and in the Mount Amiata (Tuscany, Italy); the mountain Avala (Serbia); Huancavelica (Peru); Murfreesboro, Arkansas (United States); Terlingua, Texas (United States); 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. 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 at the present day, such as from the hot waters of Sulphur Bank Mine in California and Steamboat Springs, Nevada.

Structurally, cinnabar belongs to the trigonal crystal system. It occurs as thick tabular or slender prismatic crystals or as granular to massive incrustations. Crystal twinning occurs as simple contact twins. Note, 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 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.

Cinnabar was used for millennia to create bright red pigments. In China, the mineral was used in the production of brilliant red lacquers. The mineral has also been a historically important source of mercury, which used to be part of many industrial processes, and was incorporated into tools such as thermometers and barometers. Due to mercury's toxicity, though, its use (and the use of the cinnabar from which it is gathered) has declined in modern times.

Cinnabar has historically been associated with beauty and royalty. This is not much of a surprise since it was historically used to make brilliant pigments and was even utilized as a sort of rouge. The tombs of Olmec royalty, dating back to the 7th century AD, were found to use cinnabar decorations extensively. In ancient China, such pigments were used for writing on oracle bones, and some Chinese alchemists believed the mineral could be transmuted into gold.

Cinnabar is essentially found in 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 also appear in Giza (Egypt); Puerto Princesa (Philippines); New Almaden (California); Hastings Mine and St. John's Mine, Vallejo, California (United States); Idrija (Slovenia); New Idria, California (United States); Moschellandsberg [de] near Obermoschel in the Palatinate; La Ripa, at the foot of the Apuan Alps and in the Mount Amiata (Tuscany, Italy); the mountain Avala (Serbia); Huancavelica (Peru); Murfreesboro, Arkansas (United States); Terlingua, Texas (United States); 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. It has been found in Dominica near its sulfur springs at the southern end of the island along the west coast.

The name comes from Ancient Greek: κιννάβαρι (kinnabari), a Greek word most likely applied by Theophrastus to several distinct substances. Other sources say the word comes from the Persian: شنگرف‎ shangarf (Arabicized as زنجفرة zinjifra), a word of uncertain origin. In Latin, it was sometimes known as minium, meaning also "red cinnamon", though both of these terms now refer specifically to lead tetroxide.

Cinnabar is believed by some to purify both the body and the mind. With regards to the body, this means the removal of toxins and purification of the blood. With regards to the mind, this means a clarity of thought, which better allows one to pursue truth and their higher purposes. It should be placed inside a box and not in direct contact with the skin. Cinnabar is also associated with fire, and with the sacral and root chakras.