Sand Calcite
South Dakota
A complete, double terminated crystal of sand calcite with a partial crystal attached. This type of mineral is composed of about 1/3 calcite and 2/3 sand but retains the shape of calcite crystals.
This piece is probably from Rattlesnak Butte. It was purchased from the estate of a collector who died in the mid 1960’s and the only label on the box said "S. Dakota", so the exact location can not be determined.
It is thought to have formed from wind driven sand from ancient sand dunes. A close-up view (bottom photo) reveals that the sand may include quartz, albite, tourmaline, zircon, garnet, staurolite, microcline, magnetite and other minerals.
2.7 x 1.3 x 1.1 inches
6.9 x 3.3 x 2.8 cm
Item 24123