Abstract: In accordance with the present invention, there are provided methods for enhancing the color of gemstone(s) by subjecting a combination of a gemstone and at least one finely divided form of a selected treating agent including the element copper to a temperature in the range of about 700° C. up to about 1000° C., for a time period in the range of about 3 hours up to about 600 hours, under conditions suitable to enhance the color of the gemstone, wherein the treating agent consists of a finely divided form of the selected treating agent such as copper metal or copper oxide, and wherein said gemstone is topaz or sapphire and the enhanced color lies in the color spectrum of light yellow to red.

Abstract: In accordance with the present invention, there are provided methods for enhancing the color of gemstone(s) by subjecting a combination of a gemstone and at least one finely divided form of a selected treating agent to a temperature in the range of about 700° C. up to about 1000° C., for a time period in the range of about 3 hours up to about 600 hours, under conditions suitable to enhance the color of the gemstone, wherein the treating agent consists of a finely divided form of a selected treating agent, and wherein said gemstone is topaz or sapphire and the enhanced color lies in the color spectrum of light yellow to red.

Abstract: Color enhanced topaz, beryl, tourmalines, quartz, diamonds and other gem material products, both natural and synthetic, and the process by which they are color-enhanced are described. In this process rough or finished gemstones of virtually any size, in particular very large single pieces weighing approximately one hundred carats up to 10 kilograms, are placed in a very high energy gamma ray field for extended periods of time, on the order of 50 hrs to 1000 hrs, or more, to give total exposures of 400 megagards up to 8000 megagards. The gamma flux used may be in the range of 0.5 MEV up to 30 MEV or more. In particular, the rays will be substantially higher energy than those available from conventional cobalt 60 or cesium 137 and similar sources.