Jade
WHAT IS IT?
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Thought to be of one variety until 1863, when Jadeite and Nephrite were identified
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Confused with Serpentine which is softer (2.5 to 4 versus 6 to 7).
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Serpentine is also called "False Jade" or "Teton Jade" (often dyed to deceive buyers)
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A form of Chatoyant Actinolite is known as "Cat's Eye Jade", but is not a true Jade
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Chrysoprase is marketed as "Australian Jade", but is not a true Jade (It is chalcedony)
JADEITE
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A Metamorphic Pyroxene mineral with the composition NaAlSi2O6
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Harder and generally rarer than Nephrite
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Hardness: 5 to 7 (Quartz is 7)
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Formed under high pressure at low temperatures
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Metamorphizes from Albite (NaAlSi2O8)
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Color:. Pale to Deep Green, Blue-Green, Pink, Lavender, Black
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Iron, Chromium and other trace elements contribute to the color
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Primary source of gem-quality jadeite: Myanmar ("Burmese Jade")
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Other sources: British Columbia, California, Guatemala, Italy, Japan, NZ, Russia, Turkestan
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Considered the "Imperial Gem" in China
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Introduced into China from Burma in 1784 (prior to 1784 all Chinese jade was Nephrite)
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"lmperial Green" jade from Myanmar most prized in China (can be as expensive as diamond)
NEPHRITE
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A Metamorphic Calcium-Magnesium Silicate: Ca2(Mg, Fe)5Si8O22(OH)2
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Darker Nephrite consists of iron rich Actinolites
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Lighter Nephrite contain more Magnesium rich Tremolite
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Hardness: 6 to 6.5
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Color: Grays & Greens common; Brown, Yellow, White less common
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White to Pale Yellow "Mutton Fat" Nephrite from Khotan, China is rare & expensive, often exceeding the price of Gold (up to $3000 per ounce)
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Chinese "Chicken Bone" Nephrite is Opaque White and may have a light gray or brown tint with a coarse chalky texture
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Largest source: British Columbia, Canada (5% of B.C. Nephrite is of prime quality)
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Other sources: Australia (largest black jade deposit), China, Korea, NZ, Poland, Siberia, Taiwan, USA(AK, CA, WY mainly)
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Best quality deposits: B.C, Siberia
WHAT IS IT USED FOR?
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Neolithic weapons (jade was used before metals were available because of its toughness)
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Ceremonial & decorative objects (esp. In China)
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Was believed to cure kidney stones when rubbed on the body
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The Maori of New Zealand used Nephrite to make weapons & Ornaments. The southern island was known as "The Land of the Greenstone Water”
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Jewelry is made from "Greenstone" Nephrite in New Zealand (most of the raw material is now imported from B.C.)
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Currently used for ornamental purposes Carvings, Beads, Cabochons & for homeopathy