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nephrite jade

 

Nephrite Jade


Consumer Information
 
What color is it?: The nephrite variety of jade will be medium dark green with mottled black streaks running through it as shown above and below.
 
What is the story behind this gemstone?: The term nephrite is used to distinguish a gemstone that is associated withjadeite as being part of the jade family. Actually they are two different stones with some distantly similar properties, but due to their similarities in color and use in carvings in China they have come to be related to each other if in name only. However, nephrite does have some properties that jadeite will not have. Particularly in rarity and durability. Nephrite jade is found in huge boulders off the coasts of California and Western Canada. Jadeite is not nearly as plentiful. And nephrite is more durable, which means it is used more widely for carvings.
 
Can I wear it everyday?: Absolutely. Nephrite is one of the longest wearing of any gem material.
 
Is it expensive?: Not really. Fine quality carvings such as the bear above will cost in the $50.00 to $100.00 range. The nephrite itself is only part of the issue of price, however. Fine quality carvings by true artists will lend additional cost to the item...and rightly so.
 
Is it a birthstone?: No.
 
What do I need to know before going shopping?: Remember that there are several other gemstones out on the market that will imitate nephrite. But the problem is that they are not as durable. So be sure and stay with a reputable jeweler or carver when shopping for items made of nephrite. And, remember that the artistic work done on the item of nephrite may dictate the price more than the gemstone itself.

General Information
 
Source: Canada, United States, Mexico, and Australia are major world producers. Other sources world-wide.
 
Chemical: Ca2(MgFe)5(Si4O11)2 a calcium magnesium, iron silicate.
 
Formation: Igneous rocks
 
Crystal System: Monoclinic although rarely found as crystals
 
Unusual Properties: Ability to take a carved edge. There is a story told at the GIA about an old jewelry store that burned. The only objects that survived the fire were the expensive nephrite carvings. Even though the carvings were on the top shelf and fell all the way to the floor. The toughness of the stone allowed them to survive. Excellent for tough wear and tear by any consumer.

Gemological Information
 
RI: 1.600 - 1.627
 
Birefringence: .027
 
Optic Character: B -
 
Specific Gravity: 2.90 + -
 
Hardness: 6.5 but toughness is much higher
 
Transparency: Generally opaque
 
Special Identifying Properties and Tests: Spectroscope absorption at 509 is diagnostic. RI, SG, and spectrum should be diagnostic from most imitations.
 
Synthetics: None known.
 
Imitations: Many possible including amazonite, aventurine, bowenite, californite, and chrysoprase, to name a few.
 
 

 

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