SAND CALCITE CRYSTALS - South Dakota, USA

The ‘sand calcite’ crystals of Rattlesnake Butte are well known. They formed in sandstone and the sand is incorporated into the calcite crystal as it grows. They are also known as calcite sand pseudomorphs.

The locality is controlled by the National Park Service and collecting is restricted. These specimens are from an old collection. They are presented in a plastic display box.