Gemological Information for Calcite

Color: Transparent, Colorless and most other colors
Crystal Structure Hexagonal (trigonal)
Refractive Index: 1.486 to 1.658
Durability: Single Crystal=Poor Aggregates=Fair to Good
Hardness: 3
Similar Stones: Aragonite, Chalcedony, Coral, Alabaster
Treatments: Dyeing, Impregnation with Wax and Plastic, Irradiation
Country of Origin: Mexico, U.S.

Calcite Care

Ultrasonic Cleaning: Never
Steam Cleaning: Never
Warm Soapy Water: Usually Safe
Chemical Attack: Effervesces to Certain Acids
Light Sensitivity: Natural Colors Stable
Heat Sensitivity: Decrepitates at Higher Temps


Gem Reference Guide, Los Angeles: Gemological Institute of America, 1988. Pp. 41-43.

Schumann, Walter. Gemstones of the World, New York: Sterling Publishing, Co., 1977. Pp. 208.