Witherite

This sample of Witherite is displayed in the Smithsonian Museum of Natural History. Witherite is a carbonate mineral which contains barium with the composition BaCO₃. This sample is about 9x5 cm and is from Alston Moor, Cumbria, England. In this sample it is appears together with alstonite.

A closer view of the crystals in the sample above.