A form of gypsum that contains half a molecule of water for each molecule of calcium sulfate, often used in construction materials. Dolomite: A type of carbonate mineral that is composed of ...

The 275-square-mile dune field was once underwater of the 1,600-square-mile Lake Otero, which dried up 10,000 years ago and left minerals ... it’s not as cool. However, since gypsum reflects ...