gems, topaz, irradiated topaz

A parcel of 100 deep blue irradiated topaz stones imported from Brazil was found to exhibit radioactivity levels slightly above natural background levels. Analysis revealed that the stones had been treated with neutrons in a nuclear reactor. While most irradiated topaz in the trade is not radioactive, this case highlights the importance of routine testing. For the safety of jewelers, it may be prudent to test not only topaz but also other gemstones such as beryl, green diamonds, and red tourmaline—and potentially all gemstones—for radioactivity.