Mg₆Cr₂CO₃ (OH)₁₆ .4H₂O

This sample of stichtite is displayed in the Smithsonian Museum of Natural History. Stichtite is a carbonate mineral of magnesium and chromium. It has the composition Mg₆Cr₂CO₃(OH)₁₆.4H₂O. This sample is about 8x8 cm and is from Dundas, Tasmania, Australia.