Tyrolite

arsenate

tennantite

Formula: Ca2Cu9(AsO4)4(CO3)(OH)8.11H2O
Hydrated arsenate containing hydroyl
Specific gravity: 3 to 3.25
Hardness: 1½ to 2
Streak: Paler than unpowdered colour
Colour: Turquoise-blue, blue-green; light bluish green in transmitted light.
Solubility: Soluble in acids and ammonia
Environments:

Hydrothermal environments

Tyrolite is an uncommon secondary mineral in the oxidised zone of copper deposits, typically formed by alteration of tennantite and associated with tennantite, erythrite, malachite, azurite, brochantite, chrysocolla, aurichalcite, cuprite and iron oxyhydroxides.
In the Tintic district, Utah, USA, tyrolite is associated with chalcophyllite and conichalcite.

Common impurities: S,O

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