Hessite

Hessite

Hessite and Quartz specimen from Botés, Alba County, Romania, featuring unusually thick and stout crystals of this rare silver telluride mineral. Size 3.6 x 2.2 x 1.5 cm.
General
Category Sulfide minerals
Formula
(repeating unit)
Ag2Te
Strunz classification 2.BA.30c
Crystal system Monoclinic
Crystal class Prismatic (2/m)
H-M symbol: (2/m)
Space group P21/c
Unit cell a = 8.13, b = 4.48
c = 8.09 [Å]; β = 112.9°; Z = 4
Identification
Color Lead-grey, steel-grey
Cleavage Indistinct on {100}
Tenacity Sectile
Mohs scale hardness 2 - 3
Luster Metallic
Streak black
Diaphaneity Opaque
Specific gravity 8.24 - 8.45
Optical properties Anisotropic

Hessite is a mineral form of disilver telluride (Ag2Te). It is a soft, dark grey telluride mineral which forms monoclinic crystals.

It is named after Germain Henri Hess (1802–1850).

Hessite is found in the US in Eagle County, Colorado and in Calaveras County, California and in many other locations.

Stützite (Ag7Te4) and empressite (AgTe) are related silver telluride minerals.

References

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