Tyrolite is a hydrous calcium copper arsenate carbonate mineral with the formula CaCu<sub>5</sub>(AsO<sub>4</sub>)<sub>2</sub>CO<sub>3</sub>(OH)<sub>4</sub>â 6H<sub>2</sub>O. Tyrolite forms glassy, blue to green orthorhombic radial crystals and botryoidal masses. It has a Mohs hardness of 1.5âÂÂ2.0 and a specific gravity of 3.1âÂÂ3.2. It is translucent with refractive indices of nñ = 1.694, nò = 1.726, and nó = 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 in Schwaz, Tyrol, Austria.
<br>