corundum, treatments.6, gems

The impact of enhancements on the gem market in the 1980s may be unparalleled in the history of the industry. Heat treatment introduced hundreds of thousands of carats of blue and fancy-color sapphires and rubies into the trade, while irradiation transformed millions of carats of white topaz into appealing blue gemstones. The filling of surface-reaching fractures in diamonds added a completely new factor to the assessment of color and clarity. One of the key challenges for gemologists during this period was the identification of these and other treatments. This article reviews the enhancements introduced or significantly used during the decade, with a focus on their detection using standard gemological techniques.