Cinnabar
Image: Robert M. Lavinsky (CC BY-SA 3.0)
Mineral NameCinnabar
Chemical FormulaHgS
Mohs Hardness2.5
Crystal Systemtrigonal
Lusteradamantine
Streak Colorscarlet to reddish-brown
Cleavageperfect prismatic {1010}
Fractureuneven
Specific Gravity8.1
Colorsred, scarlet, reddish-brown
Transparencyopaque
Type LocalityMcDermitt Mine (Cordero Mine; Old Cordero Mine), Opalite District, Humboldt County, Nevada, USA
Mineral GroupSulfides
Usesmercury ore, pigment, collector
Associated Mineralscorderoite, quartz, pyrite
Rarityuncommon
Description
This specimen features bright red, crystalline cinnabar, likely intergrown with or on a matrix containing corderoite, which appears as darker, smaller crystals.
Geological Context
Cinnabar forms in low-temperature hydrothermal veins and hot spring deposits, often associated with recent volcanic activity. It precipitates from alkaline solutions rich in mercury.
