Hessite

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

Hessite
General
Category	Sulfide minerals
Formula (repeating unit)	Ag2Te
IMA symbol	Hes^[1]
Strunz classification	2.BA.30c
Crystal system	Monoclinic
Crystal class	Prismatic (2/m) (same H-M symbol)
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
References	^[2]^[3]

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

1. Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
2. Webmineral
3. Mindat.org

 

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