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
Crystal habit (foliated/lamellar (layered), dendritic, bladed, acicular, lenticular, tabular (tablet shaped)). Crystal habit In mineralogy, crystal habit is the characteristic external shape of an individual crystal or crystal group. A single crystal's habit is a description of its general shape and its crystallographic forms, plus how well developed each form is. Recognizing the habit may help in identifying a mineral. When the faces are well-developed due to uncrowded growth a crystal is called "euhedral", one with partially developed faces is "subhedral", and one with undeveloped crystal faces is called "anhedral". The long axis of a euhedral quartz crystal typically has a six-sided