Tyrolite
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Tyrolite is a hydrated calcium copper arsenate carbonate mineral with formula: CaCu5(AsO4)2CO3(OH)4·6H2O. Tyrolite forms glassy blue to green orthorhombic radial crystals and botryoidal masses. It has a Mohs hardness of 1.5 to 2 and a specific gravity of 3.1 to 3.2. It is translucent with refractive indices of nα=1.694 nβ=1.726 and nγ=1.730.
It is a secondary mineral formed by the weathering of associated copper and arsenic minerals. It was first described in 1845 for an occurrence near Innsbruck, Tyrol, Austria.