In The Loupe: Advertising Diamonds, Gemstones, and Pearls

Federal Trade Commission

Bureau of Consumer Protection

Office of Consumer and Business Education

(202) 326-3650

If you advertise or sell jewelry, your product claims must be accurate. The Federal Trade Commission acts in the interest of all consumers to prevent deceptive and unfair acts or practices. The Commission's Jewelry Guides explain how to describe jewelry products truthfully and non-deceptively. This brochure addresses marketing claims about diamonds, gemstones, and pearls. Sellers may need to focus particular attention to make sure that descriptions about these products are not misleading and that important, material information is disclosed to consumers.

Diamond Weight

Decimal Representations

If the diamond's weight is described 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. If the weight is given to only one decimal place, it should be accurate to the second decimal place. That is, if you say a diamond weighs .5 cart, the diamond should weigh between .495 - .504 carat.

Fractional Representations

If the diamond's weight is described in fractions, the fraction may represent a range of weights. For example, a diamond described as 1/2 carat could weigh between .47 - .54 carat. If you use this method, you should disclose two things: the fact that the diamond weight is not exact and the reasonable range of weight for each fraction or the weight tolerance being used.

Disclosures in Catalogs and Printed Materials

If you make fractional representations of diamond weight in catalogs or other printed materials, you should disclose--clearly and conspicuously on every page with the representation--that the diamond weight is not exact. You can give the range of weights for each fraction or the tolerances used on a separate page of the catalog or materials, as long as you state, on every page that includes a fractional representation, where the consumer can find the information. For example, your catalog may say "Diamond weights are not exact. See the chart on page x for weight ranges."

Diamond Testers and Moissanite

Thermal testers used to distinguish diamonds from cubic zirconia may not accurately identify lab-created moissanite--a gemstone that resembles a diamond. Because this laboratory-created gem may falsely register as a diamond on your thermal detector, you should ensure that you recognize moissanite for what it is. For example, newer testers can do this or you may need to learn other ways of distinguishing moissanite from diamonds.

Gemstone Treatments

Gemstone treatments or enhancements refer to the way some gems are altered or treated to improve their appearance or durability. For example, impregnating some gems with colorless oils or wax masks a variety of imperfections, hides cracks, and improves color. Injecting resins into the cracks--fracture filling--hides cracks or fractures in gems.

The Jewelry Guides advise that you tell consumers that a stone has been treated when the treatment is not permanent

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or when the treated stone requires special care. You should also tell consumers that the treatment is not permanent, if that's the case. If special care is required, you should give the consumer instructions. Disclosure of other treatments that do not fall into one of these two categories generally makes good business sense.

The following are examples of disclosures that are suggested by the Guides. If the color of a treated gemstone will fade over time, you should tell the consumer that the gemstone has been treated, the treatment is not permanent and the stone's color will fade over time. If ultrasonic cleaners and other solvents should not be used to care for a treated stone, you should tell the consumer that the gemstone has been treated and which cleaners or solvents should not be used to care for the stone.

You may make these disclosures at the point of sale. However, the disclosures also should be made in any solicitation where the treated gemstone can be purchased without the consumer seeing the actual item. For example, these disclosures about treated gemstones should be made in mail order catalogs, on televised shopping programs and in certain online advertisements.


You should tell consumers if the pearls that you are selling are cultured or imitation. Your ads should not use the word "pearl"--without qualification--unless the advertised product consists only of natural pearls. If the product contains cultured pearls, the word "cultured," "cultivated," or another word or phrase with the same meaning should immediately precede the word pearl. If the product contains imitation pearls, the word "artificial," "imitation," "simulated," or another word or phrase with the same meaning should immediately precede the word pearl.

Because the dye on black pearls may not be permanent, you should tell consumers whether the black pearls they're considering are naturally black or dyed.

For More Information

To learn more about making accurate representations of diamonds, gemstones, pearls, and other jewelry products, including gold, silver, and platinum, ask for a free copy of the FTC's Guides for the Jewelry, Precious Metals and Pewter Industries. Contact: Consumer Response Center, Federal Trade Commission, Washington, D.C. 20580; 202-FTC-HELP (202-382-4357); TDD: 202-326-2502. You also can visit us at on the World Wide Web. Click on BusinessLine.

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J. Thomson Custom Jewelers
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Oklahoma City, OK 73132
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Copyright 1994-2005 J. Thomson Custom Jewelers