CaCu₅(AsO₄)₂(CO₃)(OH)₄.6H₂O

This sample of tyrolite is displayed in the Smithsonian Museum of Natural History. Tyrolite is an carbonate mineral of copper and arsenic. It has the composition CaCu₅(AsO₄)₂(CO₃)(OH)₄.6H₂O. This sample is about 8x16 cm and is from Brixlegg, Tyrol, Austria.