CaC₂O₄.H₂O

This sample of Whewellite is displayed in the Smithsonian Museum of Natural History. Whewellite is an carbonate mineral of calcium with the composition CaC₂O₄.H₂O. The sample at left is about 5x7 cm and is from Hartenstein mine, Sachsen, Germany.

Named after William Whewell (1794-1866), English naturalist and scientist, Professor of Moral Philosophy and inventor of the system of crystallographic indexing.