Most gem zircons are found as waterworn pebbles in gravel deposits in Thailand, Cambodia, Vietnam, and Sri Lanka. They are typically brown, reddish-brown, green, or yellow in color. Virtually all zircon gemstones used in jewelry have been heat-treated to enhance their colors, producing blue, golden and some colorless stones. Zircon's dispersion and brilliance is almost as good as that of diamond. However, its inferior hardness and brittleness reaveal zircon as an imposter. It is unfortunate that zircon's reputation as a diamond simulant has undermined its popularity. Today natural zircon is sometimes confused with synthetic cubic zirconia, which is used in fashion jewelry to simulate diamond.
The beautiful natural green zircon is the centerpiece of the “George Pendant,” named after George Crevoshay who cut the cabochon gem. Large gem-quality crystals of zircon are scarce. Most gem zircons are found as water worn pebbles in gravel deposits in Thailand, Cambodia, Vietnam, and Sri Lanka and are typically brown, reddish-brown, green or yellow. Virtually all zircon gemstones are heat-treated to enhance their colors; this type of treatment also produces blue zircons. This zircon is from the Ratnapura mines of Sri Lanka. Because of its large size and the fact that this green zircon has not been treated, it is a rare and wonderful addition to the National Gem Collection. Surrounding the zircon are four green tourmalines from Maine, California and Africa (5.05 carats total weight). The 18k yellow gold handmade pendant designed by Paula Crevoshay is the first piece of zircon jewelry in the National Gem Collection. It was generously gifted in 2005.