DOLOMITE
(the specimen on the right, from Ireland)
Calcium Magnesium Carbonate. Dolomite is found as colourless, white, pink, or yellow crystals. It is found in limestones and marbles, the best crystals are from Italy, Switzerland, Germany and the USA. It is used to make magnesia, which has important medicinal applications.
Hardness: 3 1/2 - 4
Dolomite, scattered over with chalcopyrite, Rush, Arkansas, USA