Fake Diamonds

Certain laboratory-created gemstones, such as lab-created moissanite, also resemble diamonds and may not be adequately detected by the instruments originally used to identify cubic zirconia. An fake diamond is one that looks like a diamond, but has a totally different physical makeup.

Fake diamonds, such as cubic zirconia, resemble diamonds in appearance but are much less costly. Cubic Zirconia is created by heating yttrium oxide and zirconium oxide. These stones have remarkable clarity and if cut correctly are extremely hard to tell from a diamond with the naked eye. The physical properties of hardness, refractive index and specific gravity are very different from a true diamond. Simulant, imitation is a material that imitates the appearance of a gem without duplicating its properties (glass, plastic, etc.). Artificial synthetics: these are the manufactured stones that have no natural counterpart and include: strontium titanate, yttrium aluminate (YAG) and cubic zirconia.

The simplest method to detect imitations consists in tracing a black line on a quite white paper sheet and to place the table of the stones to be tested on the black line. If you see the black line through the stone, it's an fake. Be careful, with cubic zirconium oxide, synthetic rutile, fabulite and certain doublets which escape this rule.

How to avoid buying a fake diamond:

• Ask if the stone is a genuine diamond or if it is a cubic zirconia, moissanite or other synthetic substance. A reputable jeweler will give you an honest answer.


• Look at the setting and mount. Since stones such as cubic zirconia are so much cheaper than diamonds, they are sometimes set in inferior metals.


• Check the wear and tear on the stone. A cubic zirconia is not as durable as a diamond and may show signs of scratches or nicks.


• Take the stone to a trusted jeweler. Looking through a jeweler's loupe, he or she should be able to spot a fake stone right away. If the jeweler cannot tell by examining the stone, he or she will have instruments that can verify its authenticity.


• It is highly recommended that you obtain a certificate from the Gemological Institute of America (GIA). The GIA, the largest impartial diamond grading authority in the world, issues a grading report after it examines the diamond and details it specifications.


• Have the stone appraised by an independent appraiser who is affiliated with a professional organization such as the American Society of Appraisers (ASA). Ask for a certificate indicating the value and characteristics of the stone.

If a cubic zirconia is mounted in a high-quality diamond mount made of 18-karat gold or platinum, you are not likely to be able to spot the fake diamond unless you're an expert.

These days, some of the best imitation diamonds are made of moissanite. This substance, which didn't come on the market until 1998, so closely resembles a diamond that even experts have a hard time telling the two stones apart without a special instrument. Moissanite sells for about one-tenth the price of diamonds.