Cubic Zirconia: Os That A Diamond? |
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Cubic zirconia, also known as CZ, and not to be confused with the zirconium silicate zircon, is a laboratory-created stone of transparency to which colors can be added. It is rated a 8.5 on the Mohl's hardness scale, and is very dense. It is widely used as a synthetic diamond, and well-know to the public. It comes close to a diamond's brilliance. It does not reach the hardness of a diamond, however, but is harder than many other gemstones, except for the ruby, sapphire, and chrysoberyl. The product Diamonique of the QVC internet shopping network is a prime example.
Because it is durable; closely resembles the diamond; and is of relatively low cost; it has been the most successful alternative to the diamond since commercial production began in 1976. Its evolution began when scientists were seeking material to use in lasers and other optical applications. By 1980, after the Swarovsky Company producers of kead crystals started producing cybic zironia, the annual production worldwide had reached fifty million carats.
In 1899 German mineralogists discovered natural cubic zirconia, and thinking it was a by-product, chose not to give it a name. The high melting point of zirconia prevented single crystal growth as no crucible could hold it in a molten state. Y. Roulin and R. Collongues in 1960 France were heavily involved in the single crystal growth of cubic zirconia, but their process called "cold crucible" only resulted in small crystals. Soviet scientists of the Lebedev Physical Institute then perfected the procedure, called "skull crucible," and their findings were published in 1973. With minor variations this process is still used today, and trace elements are added in order to provide various colors. If stones do not measure up in clarity, they are not used. They are measured in millimeters rather than carats.
The cubic zirconia of today has been so perfected that only the trained eye can differentiate it from a diamond, and only by using a loupe or a microscope. Ironically, cubic zirconias have no flaws, while diamonds do. The facet cuts of some CZ's appear different from a diamond. The refractive index of a CZ is a little less than a diamond, and CZ's are 75% heavier. However, the additional fire (flashes or rainbow colors) of the CZ can be seen even by an untrained eye. The CZ can be truly colorless, while the diamond have a slight hue of yellow or brown. Once thought inferior, CZ's of jewelry today can be found in sterling silver, 14 Karat, and 18 Karat gold, and even platinum.
Care should be taken when wearing CZ jewelry. Althought it is hard. It is also brittle and should be removed when doing heavy tasks. It is even possible for a diamond to chip under these circumstances. Also remove the pieces before cleaning or taking a shower as soap amd some cleaning agents can dull the surface, This is also true of subjecting it to cosmetics or powder.