Sulfate Minerals, Carbonate Minerals, and Borate Minerals

Sulfate minerals contain a negative ion that combines sulfur and oxygen. They include gypsum and barite. A sword-like gypsum crystal from the Udo mine in Shimane Prefecture is the largest in Japan.

Carbonate minerals contain a negative ion that combines carbon and oxygen. They include calcite and rhodochrosite. Even crystals of the same calcite take different shapes.

Borate minerals contain a negative ion that combines boron and oxygen. Ulexite, which is in this group, is called a television stone as the letters underneath the stone seem to be floating above.