Gaspeite: Gemstone Information
Gaspéite is a member of the calcite group with the composition (Ni,Mg)CO3. It occurs as translucent bright grass-green to olive- or yellowish green nodular concretions or as aggregates of rhombic crystals (too small for use) of the trigonal system. The hardness is 4.5–5 and the SG near 3.7. The RI for the ordinary and extraordinary rays is 1.83 and 1.61,uniaxial negative with a birefringence of 0.220. Gaspéite is uncommon,occurring as a secondary mineral in a Ni-sulphide vein in metamorphosed siliceous dolostone at the Gaspé Peninsula, Quebec, Canada.