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Zircon
Specimen | Catalog Number | Locality | Weight |
---|---|---|---|
Zircon | NMNH G10661 | Madagascar, Andolakaka | 7.46 ct |
Most gem zircons are found as waterworn pebbles in gravel deposits in Thailand, Cambodia, Vietnam, and Sri Lanka. Other localities include Burma, Madagascar, Brazil and Tanzania. Zircon is typically brown, reddish-brown, green or yellow. Since the 1920s virtually all zircon gemstones used in jewelry have been heat-treated to enhance their colors, producing blue, golden, and some colorless stones. Colorless zircon outperforms any other mineral imitating diamond as its dispersion and brilliance are almost as good as that of diamond. However, its inferior hardness and brittleness reveal zircon as an imposter. Like diamonds, zircons are typically cut as round brilliants to best show their dispersion or fire. The most popular zircons are the blue, colorless, and golden gems produced by heating. This triangular-cut golden zircon weighs 7.46cts and is from Madagascar. It is the first zircon from this locality in the National Gem Collection.