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Subject:Re: Failed jade test, Help?
Posted By: Super Thu, Jan 01, 2015
I would not necessarily call it a failed jade test yet.
First of all, I do not know how you measured the SG of your piece. I usually used a Swiss-made Pesola 100 gram spring balance to measure the S.G. of small pieces. I found it much more accurate than using other methods.
I also found that although a high SG does not always equate high quality of jade but it is not often one would find a nephrite jade piece with a SG of 3.0 or higher. As a matter of fact, out of the 1000 nephrite jade pieces/rocks/slabs I had measured, I believe less than 5% were with SG of 3.0 or higher. They usually fell in the range of 2.90 - 2.96, even with Hetian nephrite jade.
I am also not so sure how accurate you can perform a "MOH hardness test" with a needle because:
(1) If a needle is sharp enough, you can almost definitely scratch the surface of a piece;
(2) It really depends on the material of the needle (or pocket knife) was made of. While the hardness of metal (iron) is around 5 but needle or pocket knife (like Swiss Army) that were made of good steel may have a hardness of 6;
(3) Some time pieces consisted of different mixtures of material and therefore if different areas of a piece is being tested, it may have different hardness.
The only tools you can really use to test the MOH hardness of any jade pieces pretty accurately, IMHO, is to purchase a MOH hardness testing pick set made by the Mineral Lab:
http://www.mineralab.com/Hardness.htm
You can also find it for sales in Amazon.com but the people at Mineral Lab were very helpful.
The hardness picks you really need are 5, 6, 7 and if they would just sell you those three picks, it would save you a lot of money.
Usually nephrite pieces would not be scratched by the 5 pick but may be by the 6 and almost definitely by the 7 (I did encounter one Hetian nephrite jade piece that resisted the 7 pick)
I believe if you can confirm the exact MOH hardness of your dog and if it is greater than 5 but less than 6 with a MOH hardness set, then it could be made of low-grade grey color Kulun mountain nephrite jade. It would also be good if you can confirm its SG with a Pesola spring balance.
http://www.forestry-suppliers.com/product_pages/Products.asp?mi=63941&title=Pesola%20Micro-Line%20Spring%20Scale,%20100g/3-1/2oz%20x%201g/1/16%20oz.&itemnum=93628
Good luck.
Super
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( China & Japan ) - Jim - Dec 31, 2014 (07:45 AM) 
