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Enhanced Gemstones

People have been enhancing gemstones since they first picked up a colorful shiny rock and rubbed it clean. However, the proliferation of enhancement methods and the tendency of sales people to be less than forthcoming about the true nature of a gemstone has caused the buying public to become leery. The GIA has made it a priority to teach their students to identify enhanced gemstones. Here are a few of their pointers on the subject of Topaz.

PINK - while pink occurs naturally, it can also be produced by thermal enhancement. Brownish yellow to orange "Imperial topaz" when heated, will turn pink. This thermal treatment causes a change in the stone's short wave fluorescence. A natural stone will fluoresce very weakly or moderate chalky yellow-green. A treated stone will fluoresce much stronger.

GREEN - green topaz is very rare in nature and therefore enhancement should be suspected. Some "Ocean Green Topaz" is being sold alongside the more common irradiated blue topaz. The original topaz material is believed to have come from Sri Lanka.

Like the blue, these stones ranging from yellow green to blue green are also potentially radioactive. The color is unstable and is reported to fade back to pale blue after less than 12 hours of exposure. GIA points out that the greatest challenge faced by the jewelry trade in the 1990's was the detection and disclosure of gem treatments, and this will true in the 21st century as well. Be aware of the marketplace.

Via Golden Spike News 12/01