Feature Gems & Gemology, Summer 1992, Vol. 28, Issue 2

Gamma-Ray Spectroscopy to Measure Radioactivity in Gemstones

Over the last several years, the trade has seen a number of radioactive gemstones.  While a Geiger counter may show the existence of radioactivity, determination of the actual type of radionuclide and the quantity present requires a more sophisticated technique, gamma-ray spectroscopy. This article reports on the use of this technique to measure the radionuclides in two radioactive gemstones, a yellowish green diamond and a large dark blue topaz.