It has been called the jewel of Imperial Russia, and the "diamond" of colored stones. It's demantoid garnet, and large quantities are found only in the Ural Mountains-or so it was thought. It now has a new source, this time in West Africa. According to Jeffrey Hayat, president of Gem Demantoid, several years of exploration and mining have enabled the company to market quantities rarely seen until now. The first production of lots reportedly consists of several thousand carats of cut fine green demantoid. The gems are available in a range of shapes and sizes. Most stones weigh between 1 ct. and 10 cts., and each has been cut to maximize dispersion and brilliance. The first showing of this new find was scheduled to take place in Tucson at February's Gem & Jewelry Exchange show.