Diamonds
A diamond's value is based on four criteria: color, cut, clarity, and carat. The clarity and color of a diamond usually are graded. However, scales are not uniform: a clarity grade of "slightly included" may represent a different grade on one grading system versus another, depending on the terms used in the scale. Make sure you know how a particular scale and grade represent the color or clarity of the diamond you're considering. A diamond can be described as "flawless" only if it has no visible surface or internal imperfections when viewed under 10-power magnification by a skilled diamond grader.

As with other gems, diamond weight usually is stated in carats. Diamond weight may be described in decimal or fractional parts of a carat. If the weight is given in decimal parts of a carat, the figure should be accurate to the last decimal place. For example, ".30 carat" could represent a diamond that weighs between .295 - .304 carat. Some retailers describe diamond weight in fractions and use the fraction to represent a range of weights. For example, a diamond described as 1/2 carat could weigh between .47 - .54 carat. If diamond weight is stated as fractional parts of a carat, the retailer should disclose two things: that the weight is not exact, and the reasonable range of weight for each fraction or the weight tolerance being used.

Some diamonds may be treated to improve their appearance in similar ways as other gemstones. Since these treatments improve the clarity of the diamond, some jewelers refer to them as clarity enhancement. One type of treatment - fracture filling - conceals cracks in diamonds by filling them with a foreign substance. This filling may not be permanent and jewelers should tell you if the diamond you're considering has been fracture-filled.

Another treatment - lasering - involves the use of a laser beam to improve the appearance of diamonds that have black inclusions or spots. A laser beam is aimed at the inclusion. Acid is then forced through a tiny tunnel made by the laser beam to remove the inclusion. Lasering is permanent and a laser-drilled stone does not require special care.

Imitation diamonds, such as cubic zirconia, resemble diamonds in appearance but are much less costly. 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. Ask your jeweler if he has the current testing equipment to distinguish between diamonds and other lab-created stones.

A Jewelry Shopper’s Checklist
When you're in the market for a piece of jewelry for yourself or someone you love, shop around. Compare quality, price, and service. If you're not familiar with any jewelers in your area, ask family members, friends, and co-workers for recommendations. You also should:

• Ask for the store's refund and return policy before you buy.
• Check for the appropriate markings on metal jewelry.
• Ask whether the pearls are natural, cultured, or imitation.
• Ask whether a gemstone is natural, laboratory-created, or imitation.
• Ask whether the gemstone has been treated. Is the change permanent? Is special care required?

Make sure the jeweler writes on the sales receipt any information you relied on when making your purchase, such as the gem's weight or size. Some jewelers also may supply a grading report from a gemological laboratory.

In addition, these tips apply when you're shopping for jewelry online:

• Shop with companies you know or do some homework before buying to make sure a company is legitimate before doing business with it.
• Get the details about the product, as well as the merchant's refund and return policies, before you buy.
• Look for an address to write to or a phone number to call if you have a question, a problem or need help.

For More Information
If you have a problem with the jewelry you purchased, first try to resolve it with the jeweler. If you are dissatisfied with the response, contact your local Better Business Bureau or local consumer protection agency. You also may contact the Jewelers Vigilance Committee's Alternative Dispute Resolution Service. This program assists consumers and businesses in resolving disputes about jewelry. The Jewelers Vigilance Committee (JVC) is an independent, non-profit organization formed to advance ethical practices in the jewelry industry. You may contact the JVC by mail: 25 West 45th Street, Suite 400, New York, NY 10036-4902, or by phone: 212-997-2002.