Gems & Gemology, Spring 1990, Vol. 26, No. 1
Gemstone Enchancement and its Detection in the 1980s
Robert C. Kammerling, John I. Koivula, and Robert E. Kane
The impact that enhancements had on the gem market in the 1980s may be unparalleled in the history of the industry. Heat treatment brought hundreds of thousands of carats of blue and fancy-color sapphires and rubies to the trade, irradiation turned literally millions of carats of white topaz into attractive blue stones, and the filling of surface-reaching separations introduced an entirely new variable to the evaluation of color and clarity in diamonds. One of the key challenges to the gemologist during this decade was the identification of these and other enhancements. This article reviews the enhancements that were introduced or played a major role during the 1980s, focusing on their detection by standard gemological techniques.