Frohbergite | |
---|---|
General | |
Category | Telluride (sulfosalt) mineral |
Formula (repeating unit) | FeTe2[1] |
IMA symbol | Frb |
Strunz classification | 2.EB.10a[1] |
Crystal system | Orthorhombic |
Crystal class | sulphide |
Identification | |
Color | white with a lilac or pinkish tint[2] |
Crystal habit | in the form of a thin border or small inclusions |
Cleavage | the mineral is fragile |
Mohs scale hardness | 3-4,[2] up to 4.5[3] |
Luster | metallic |
Diaphaneity | opaque[2] |
Density | 8.057 (calculated)[1] 8.055 (measured)[4] |
Pleochroism | extremely weak.[2] |
Frohbergite (German: Frohbergit, title by proper name: Max Hans Frohberg), also iron telluride is a rare hydrothermal mineral from the sulfide class, in composition — iron telluride with the ideal formula FeTe2 (contains 82.05% tellurium and 17.95% iron).
Frohbergite occurs in tellurium-rich veins of hydrothermal deposits, sometimes as a thin rim on the periphery of chalcopyrite or as inclusions in native gold, petzite or chalcopyrite. It belongs to the marcasite group and forms a mineral line with mattagamite. Frohbergite most often occurs as fine-grained aggregates.[5]: 93