Honey Calcite ("Onyx") Carving and Cutting Rough Calcite is the gemstone form of calcium carbonate and often erroneously
called "onyx". Calcite comes in many patterns and colors. Honey
calcite is translucent and cuts fine gemmy cabochons and beautiful carvings.
Calcite is a soft stone, so it is not a good choice for ring stones. Orange
calcite cuts easily and takes a good polish with diamond or tin oxide. Mohs
hardness 3.