- © 2009 by the Mineralogical Society of America
Treatment processes to improve the color, appearance, and/or durability of certain gemstones have been used for hundreds of years, and their variety, sophistication, and application within the jewelry trade have increased over the past several decades. Whether or not these enhancement processes are considered acceptable trade practices, their use must legally be disclosed at the time of gemstone sales. Disclosure of treatment information requires that treated gems be correctly identified by gemologists and gemtesting laboratories. Treatment detection is based upon careful documentation of the properties of gem materials, including the use of advanced nondestructive techniques for obtaining chemical and spectral data.