When shopping for a healing crystal, it’s good to know if it has been altered in any way. Many gemstones are routinely treated to enhance their appearance. So, those interested in their healing properties will want to ask a reputable dealer for full disclosure of the source and treatment of an individual stone.

Ask if a stone of interest has been heated, irradiated or otherwise chemically altered. Also inquire about its country of origin and mining and distribution process and conditions. Is there any chance that child labor or onsite chemical toxins were involved? Could the stone have been stolen, or traded on the black market?

Members of the nonprofit American Gem Trade Association have signed on to uphold the highest ethical standards in their business practices, including declaration of gemstone enhancements; they can be a good place to start. Following are some general guidelines provided by the association.

• Agate: usually dyed, but natural colors are available
• Carnelian: usually heated and occasionally dyed
• Amethyst, Aventurine, Bloodstone, Clear Quartz. Lapis Lazuli, Moonstone, Rose Quartz. Smoky Quartz: not typically treated

For more information on the composition, care and enhancement of gemstones, visit www.AddMoreColorToYourLife.com/gemstones/gem-palette.asp.

Adam Graham is marketing manager for the American Gem Trade Association.