Tiemannite

 Tiemannite is a mineral, mercury selenide, formula HgSe. It occurs in hydrothermal veins associated with other selenides, or other mercury minerals such as cinnabar, and often with calcite. Discovered in 1855 in Germany, it is named after Johann Carl Wilhelm Tiemann (1848–1899).

Tiemannite
Tiemannit.jpg
General
CategorySelenide mineral
Formula
(repeating unit)
HgSe
Strunz classification2.CB.05a
Dana classification02.08.02.04
Crystal systemIsometric
Crystal classHextetrahedral (43m)
H-M symbol: (4 3m)
Space groupF43m
Identification
ColorSteel-gray to black
Crystal habitMassive and as euhedral crystals
Cleavagenone
Mohs scale hardness2.5
LusterMetallic
Streakgrayish black
Diaphaneityopaque
Specific gravity8.19 - 8.47
References[1][2]

This article uses material from the Wikipedia article
 Metasyntactic variable, which is released under the 
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