Zirconium dioxide jewellery. Like diamond, cubic zirconia has a cubic crystal structure and a high index of refraction. Visually discerning a good quality cubic zirconia gem from a diamond is difficult, and most jewellers will have a thermal conductivity tester to identify cubic zirconia by its low thermal conductivity (diamond is a very good thermal conductor). This state of zirconia is commonly called "cubic zirconia", "CZ", or "zircon" by jewellers, but the last name is not chemically accurate. Zircon is actually the mineral name for naturally occurring zirconium silicate (ZrSiO). Zirconium dioxide Zirconium dioxide (), sometimes known as zirconia (not to be
Kassite (mineral) and in nepheline syenite in the Magnet Cove igneous complex of Arkansas, US. Its mineral association includes cafetite (which with it is also polymorphous), perovskite, titanite, rutile and ilmenite. Kassite (mineral) Kassite is a rare mineral whose chemical formula is CaTiO(OH). It crystallizes in the orthorhombic crystal system and forms radiating rosettes and pseudo-hexagonal tabular crystals which are commonly twinned. Kassite crystals are brownish pink to pale yellow in color, are translucent, and have an adamantine luster. Cleavage is distinctly visible, and the crystals are very brittle. It was first described in 1965 in the Afrikanda pyroxenite massif, a formation