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.