Calcite

These three clear calcite crystals are just the beginning of the vast variety of forms in which calcite appears. Since it is soluble in acidic water, it can be dissolved and recrystallized with a large number of different inclusions. All of the samples pictured here are on display at the Smithsonian Museum of Natural History.

Calcite, CaCO₃, is the most abundant of the carbonate minerals.

Clear calcite has many optical applications because of its large birefringence.