You may think you're an expert at spotting fake jewels, but with some of the new diamond facsimiles on the market, even a jeweler might not be able to spot the imposters.

1. 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.

2. 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.

3. 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.

4. 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.

5. 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.

6. 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.

Tips & Warnings

- 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.

- When purchasing "diamonds" online or buying stones you have not seen or had independently appraised, make sure the sale is accompanied by a grading report provided by an independent lab like the GIA. When you do make a purchase, get everything in writing.