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
Hope Diamond long been rumored to carry a curse, possibly due to agents trying to arouse interest in the stone. It was last reported to be insured for $250 million. The Hope Diamond, also known as Le Bijou du Roi ("the King's Jewel"), Le bleu de France ("France's Blue"), and the Tavernier Blue, is a large, , deep-blue diamond, and now housed in the National Gem and Mineral collection at the National Museum of Natural History in Washington, D.C. It is blue to the naked eye because of trace amounts of boron within its crystal structure, and exhibits a red phosphorescence under