Cubic Zirconia

The hard, optically flawless and colorless crystalline form of Zirconium Dioxide is known as cubic zirconia. Cubic zirconia has remained a gemmological and economical competitor of diamonds since the 1970’s due to its lower cost, durability and astonishing similarity to diamonds. Indeed, cubic zirconia is popular among jewelry makers as a synthetic gemstone. It is rapidly taking the place of expensive diamonds on rings, necklaces, pendants and earrings. The credit of discovering industrial cubic zirconia should go to German and Soviet scientists, who, in the late 18th century, melted zirconium oxide and yttrium oxide at a temperature of 2,750ºC, to form cubic zirconia crystals.

Cubic zirconia is known to be better than most other gemstones, not only because of its price but also because of the fact that it is very durable and sparkles brighter. However, a well-trained eye can distinguish between cubic zirconia and diamond because the latter has a lower dispersion rate. Indeed, today some manufacturers are capable of producing very high quality cubic zirconia, that it’s somewhat difficult to tell them apart from expensive diamonds. Not just that; cubic zirconia’s specific gravity, refractive index and thermal conductivity are all different from those of diamonds that makes it more marketable and durable. One more advantage of utilizing cubic zirconia in jewel-craft is that it can be obtained completely colorless, whereas only in rare cases, diamonds are truly colorless. Most diamonds have a hint of brown or yellow on them.

Synthesis of cubic zirconia is an interesting process. Zirconia feed powder, mixed with a stabilizer (usually calcium oxide) is packed in cup-shaped scaffold, and heat is induced. After some time, the heat is reduced, so that the melted material will start forming an even, flawless, columnar crystalline. Prolonged annealing is then carried out to get rid of the possible flaws and the annealed crystals are cut into gemstones. Addition of various minerals will decide on the colors of cubic zirconia ultimately produced. For instance, addition of chromium will make the crystals green and addition of titanium will give a golden brown finish.

The cut in any stone, precious, semiprecious, natural or synthetic, depends on the skill of the cutter. The objective of the cutter should be to remove a minimum amount of crystals in order to obtain the highest degree of clarity. A brilliant cut, which is when the dimensions are perfect, will make cubic zirconia exactly like diamonds. With all the qualities well maintained, cubic zirconia will be perfect to be embedded in any piece of jewelry.