CINNABAR
Cinnabar is a mercury sulfide mineral (HgS). It
is one of the few sulfide minerals that lacks a metallic luster (other examples
are orpiment & realgar). In its crystalline form, cinnabar has an
intense adamantine luster. Massive, fine-grained specimens generally have
an earthy luster. Cinnabar has a reddish color reddish streak, 3
different cleavage planes, is quite soft (H = 2 to 2.5), and is heavy for its
size (high specific gravity).
Cinnabar principally occurs in some young volcanic
rocks and hydrothermal spring deposits. It's a fairly volatile chemical -
much of it passes out from volcanic vents into the atmosphere as a gas.
Cinnabar is the most important ore mineral for the
element mercury and was long used as a red pigment.
Cinnabar
(red) on dolomite (whitish) from Hunan Province, South China (Dwyer Mercer
County District Library # 217-110, Celina, Ohio, USA).