Cinnabar

Cinnabar
Cinnabar on Dolomite
General
CategoryMineral
Chemical formulamercury(II) sulfide, HgS
Identification
ColorBrownish-red
Crystal habitRhombohedral to tabular. Granular to massive
Crystal systemTrigonal – Trapezohedral
CleavagePrismatic, perfect
FractureUneven to subconchoidal
Mohs scale hardness2-2.5
LusterAdamantine to dull
StreakScarlet
Specific gravity8.176
Optical propertiesUniaxial (+)
Refractive indexnω = 2.905 nε = 3.256
Birefringenceδ = 0.351
Solubility1.04 x 10-25 g per 100 ml water (Ksp at 25 °C = 2 x 10-32)[1]
References[2][3][4]


  1. Meyers, J. (1986), Chem. Ed., 63, p. 689  Check date values in: |access-date= (help); Missing or empty |title= (help);
  2. Mineral Handbook
  3. Mindat
  4. Webmineral