Calcite is not commonly an important gem mineral because it is relatively fragile and soft (3 on the Moh's scale of hardness). It is typically colorless or white, however due to impurities it can occur in shades of red, yellow, green, blue, violet, brown, and black. This lively reddish-orange calcite from a recent find in Tanzania is rare and a wonderful addition to the National Gem Collection.
Image Number: Ken Larsen
Catalog Number: G10615
Weight: 8.48 carats
Gift of Dudley Blauwet, Blauwet Gems