Gems & Gemology, Spring 2012, Volume 48, No. 1
Hiroshi Kitawaki, Yoichi Horikawa, Katsumi Shozugawa, and Norio Nogawa
Two strongly orangy pink morganites with residual radioactivity were studied. The dose rate of the samples, measured by a scintillation survey meter, ranged from 0.15 to 0.35 μSv/h. Although this radioactivity was likely not hazardous, it was above the recommended exposure limit set forth in 1990 by the International Commission on Radiological Protection. To identify the radionuclides, gamma rays from the samples were measured using a Ge(Li) semiconductor detector. The activation products 134Cs, 54Mn, and 65Zn were detected, proving that the samples had been artificially irradiated with neutrons.