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
Mineral spa Mineral spa Mineral spas are spa resorts developed around naturally occurring mineral springs. Like seaside resorts, they are mainly used recreationally although they also figured prominently in prescientific medicine. Spas were used for millennia for their purported healing or healthful benefits to those wealthy enough or close enough to partake of their waters. This was called a mineral cure and gave let to such phrases as "taking a cure" and "taking the waters". There has always been a mixture of recreational and medicinal connotations involved, from rest and relaxation, stress relief, and convalescence to more specific notions such as humorism.