grades. (Kammerling 145) The diamonds are first cleaned, then filled with a molten glass at high temperatures, cooled, and cleaned again to remove glass from the stones surfaces.Claims have been made concerning the stability and durability of various products. It is virtually impossible to determine exactly how many treated stones are in the marketplace. Recent findings by gemologists indicated that the filling material used in at least one of the treatment processes might decompose when exposed to an ultraviolet lamp or ultrasonic cleaning. The GIA has learned that, while ultrasonic cleaning for a brief period may not damage at least some fillings, extended exposure to this process may cause some shattering of, or other damage to, the filler. High temperature torches used in various jewelry repair procedures may also have adverse affects on treated gemstones. Because of industry concerns about disclosure and detection, it has been suggested that all such stones be laser-inscribed with initials to disclose the treatment. (EGL) Synthetic diamonds are also on the market. Some of the synthetics have the same exact properties as natural diamond. In 1990, scientists at the General Electric Research and Development Center (GERDC) in New York, announced the production of a new isotopically pure carbon-12 synthetic diamond. Carbon, in nature, consists of a mixture of carbon atoms that have different masses called isotopes. Natural diamond has carbon atom isotopes twelve and thirteen, as do the GERDC synthetics. (EGL) ConclusionTwo additional Cs should be mentioned. One of the most important for the consumer is the "C" in cost. The most obvious of the 4C's is the carat weight or the size of the stone, which is one of the bigger factors in determining value of a diamond. The combination of all four characteristics is the final determining cost factor. There are many different combinations of size, color, clarity and proportionin...
