Cavansite: Gemstone Information
Cavansite, resembling turquoise and with the composition Ca(V4O)Si4O104H2O is occasionally fashioned, material coming from the Poona area of India. It occurs as attractive radially fibrous crystal clusters of the orthorhombic system and can be cut into blue to green cabochons. The hardness is 3.5, the SG 2.24–2.27. The RI reading of 1.54 is all that can be seen on the refractometer. Resin impregnation has been resorted to for stabilization, the porosity of the material making the process simple.