Had a problem buying diamonds, gemstones, gold, or other jewelry?

December is a big month for jewelry sales. So if you'll be buying some glittering goods this holiday season, be aware that the jewelry you see in stores and online might have been altered to improve its appearance.

For example, a number of techniques, including laser drilling and fracture filling, might be used to remove or hide imperfections in diamonds to improve their clarity.

In addition, emeralds might be "oiled" to fill fractures and make them less apparent. Sapphires and rubies might be subjected to high heat to improve their transparency and color.

Of course, such alterations should be disclosed to you when you buy, but often they aren't.

To help you get the best deal this holiday season, we're planning a jewelry buying story for the December issue of the Consumer Reports Money Adviser, which will also be published on ConsumerReports.org. To help us spot the issues we should include (such as altered stones), we're asking you to detail any problems you've faced buying fine jewelry. Click on this online interview link to share your story and wisdom with us.

In the meantime, if you're concerned about the quality of a piece of jewelry you recently bought, bring it to a professional jewelry appraiser in your area. You can find a certified appraiser through the American Gem Society or the American Society of Appraisers.

—Mandy Walker