cinnabar (entomology) - Properties, Mining and extraction of mercury, Medicinal use, Other forms of cinnabar

A medium-sized, nocturnal tiger moth; forewings dark grey with carmine patches, hindwings carmine with black margins; caterpillar yellow and black, feeding on ragwort (Family: Compositae); overwinters as pupa; also called cinnabar moth. (Order: Lepidoptera. Family: Arctiidae.)

(Discuss)

Cinnabar
General
Category	Mineral
Chemical formula	mercury(II) sulfide, HgS
Identification
Color	Brownish-red
Crystal habit	Rhombohedral to tabular. Granular to massive
Crystal system	Hexagonal
Cleavage	Prismatic, perfect
Fracture	Uneven to subconchoidal
Mohs Scale hardness	2-2.5
Luster	Adamantine to dull
Refractive index	Transparent to opaque
Pleochroism	N/A
Streak	Scarlet
Specific gravity	8 - 8.2 g/cm³
Fusibility	?
Solubility	3.10-26 g per 100 mL water
Major varieties
None

Cinnabar, sometimes written cinnabarite, is a name applied to red mercury(II) sulfide (HgS), or native vermilion, the common ore of mercury.

Properties

Cinnabar is generally found in a massive, granular or earthy form and is bright scarlet to brick-red in color.

Cinnabar is found in all localities that yield mercury, notably Almadén (Spain), New Almaden (California), Idrija (Slovenia), New Idria (California), Landsberg, near Obermoschel in the Palatinate, Ripa, at the foot of the Apuan Alps (Tuscany), the mountain Avala (Serbia), Huancavelica (Peru), Terlingua (Texas), and the province of Guizhou in China, where fine crystals have been obtained.

Mining and extraction of mercury

Cinnabar was mined by the Roman Empire both as a pigment and for its mercury content, and it has been the main ore of mercury throughout the centuries.

Because of the high toxicity of mercury, both the mining of cinnabar and refining for mercury are hazardous and historic causes of mercury poisoning.

Medicinal use

Although cinnabar is known to be highly toxic, it is nevertheless used (as is arsenic), in powdered form mixed with water, in traditional Chinese medicine (TCM).

Other forms of cinnabar

Hepatic cinnabar is an impure variety from Idrija in Carniola, in which the cinnabar is mixed with bituminous and earthy matter.