Description
A very hard stone ranging in color from pale to dark green. Jade is composed of either the mineral jadeite or nephrite. Both are hard enough to scratch glass. Though less common, jadeite is highly valued for its translucent glassy appearance. Jadeite is primarily found in China, Myanmar (formerly Burma), and Mexico. The grass green variety of jade obtained from Myanmar is called Ayah kyauk. Nephrite is found in New Zealand, Australia, Taiwan (nephrite cat's eyes), Turkestan, Korea, Siberia, Mexico, Canada (British Columbia), and the U.S. (Alaska, California, Wyoming). Nephrite is more opaque than jadeite and produces an oily, lustrous appearance when polished. Jade has been used since prehistoric times for small utensils, carvings, vases, and jewelry. Some processing techniques have been used since the 1908s to enhance the color of inferior stones. B-jade has been bleached to remove brown stains, while C-jade has been impregnated with resins to increase its translucency. A-jade is untreated.
Synonyms and Related Terms
jadeite; nephrite; greenstone; Ayah kyauk; kidney stone; jade (Fr., Port.); pietra de la hijada (Esp.); Jade (Deut.); jade (Ned.)
| 5-6 (nephrite); 6-7 (jadeite) |
| 3.0 (nephrite); 3.3 (jadeite) |
| 1.60-1.69 |
Other Properties
Monoclinic system with fibrous or granular crystalline masses.
Luster = vitreous to waxy.
Cleavage is good in two directions
Fluorescence: nephrite does not fluoresce, jadeite may appear pale white in long UV
Dyed jade appears red when examined with a Chelsea filter.
For further information, see jadeite and nephrite records.
Additional Information
° E.West Fitzhugh, "Jade" The Dictionary of Art, Grove's Dictionaries Inc., New York, 1996.
° Michael O'Donoghue and Louise Joyner, Identification of Gemstones, Butterworth-Heinemann, Oxford, 2003
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Last updated on: 7/7/2009 10:50:07 AM
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