 The
cubic zirconia (CZ) gemstone is a man-made version of the naturally
occurring mineral zirconium oxide. The CZ was originally discovered
in nature in 1892. Unfortunately, the quantities and size of
naturally occurring CZs are such that there is too little naturally
occurring cubic zirconia to make it worthwhile to mine the crystals and
the naturally occurring crystals are too small.
The process for making cubic zirconia in the laboratory was perfected in Russia by a team of scientists working under V. V. Osiko. Their technique was first published in 1973 and commercial production of cubic zirconia began in 1976. By 1990, annual global production reached 50 million carats.
Cubic zirconia is absolutely clear, but can be manufactured in a variety of colors by adding various metals to the powder zirconium in the manufacturing process. The CZ is so optically close to a diamond that only a highly trained observer can tell the difference. One of the ways that many trained jewelers use to visually distinguish a diamond from a CZ is that a mined diamond almost always has some small trace of color frequently a very light yellow or gray when observed under a loupe. By contract a white or clear CZ will have absolutely no color. Another technique used by jewelers to distinguish a diamond from a CZ is that mined diamonds almost always have small imperfections or inclusions that can be seen using a jeweler's loupe. A CZ does not have these imperfections. A third visual technique for identifying a CZ is that a CZ has more dispersion of light and more prismatic "fire" than a diamond. Before a stone is set, a CZ can be distinguished from a diamond by the weight and by the thermal conductivity. A CZ will be 1.7 times heavier than a diamond of the same size. A CZ is also a thermal insulator like an oven mitt, while by contrast a diamond is a thermal conductor. In fact a diamond conducts heat even better than copper. Hardness is a final way to differentiate between a diamond and a CZ. A CZ has a hardness of 8.5-9 while a diamond has a hardness of 10 on the Mohs hardness scale. A CZ will not scratch a diamond, while another diamond will. This check of hardness is not recommended because it is destructive -- the stone being tested may be damaged. A CZ is an excellent choice to replace diamonds and colored gemstones in jewelry. The hardness of the CZ makes it harder than dust and suitable for everyday wear. Optically, a CZ is very hard to distinguish from a diamond. CZs, being man-made are virtually free of occlusions and other imperfections. Finally, cubic zirconia are very reasonably priced. Where a flawless 1 carat diamond would cost about $4000 or more and a Moissanite simulated diamond the same size would cost about $600, a flawless 1 carat CZ could be purchased for less than $10. Here is a question for people considering a diamond -- given that there are now processes for creating diamonds in the laboratory, might there come a time when the price of diamonds begins to decrease? In 50 years, will people be wearing gemstones that were mined, or will they be wearing gemstones that are chemically identical to mined gemstones, but without the flaws inherent in naturally occurring stones? Does a mined gemstone sound like a good long term investment? You can find more information on cubic zirconia in Wikipedia, the free encyclopedia here. Please select the picture above-right, or select here to view our selection of cubic zirconia diamond simulants. |
