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Automatic Detection Of Cracks?


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I'm new to this board and I'm also a novice in terms of diamonds.


The reason for joining is that I recently inherited a gold ring with 10 cut diamonds and me and my sister had a jeweller look at it for an evaluation. We were a very disappointed by the jeweller's verdict: It is only worth the junk price/gram of the gold... Needless to say, I'm not confident that the jeweller isn't trying to get the ring from us at a cheap price... :)


According to the jeweler each stone was cracked which he determined, without even looking at the stones, by inserting each diamond into an apparetus that automatically made a beep if there would be a crack in the stone. The jeweller also said that the stones were cut according to an old fashioned pattern.


I now wonder how such an apparatus can detect the cracks and if it is 100% proof or if it maybe can be fooled by the unusual cut?


Being a proffesional phycisist, I'm also very curious about the functional principle of such an apparatus.


Best regards, Jens

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The little beeping probe is a thermal conductivity tester and it’s a way of determining that it’s a diamond as opposed to most of the various alternatives that look sort of like diamonds. They tell you nothing at all about the quality of the stones.


What you have received is a bid, not an appraisal. That’s fine, he can bid whatever he wants, but this is in no way an unbiased assessment of what something is ‘worth’. Go somewhere else.


The bad news is that a lot of rings, including many rings with multiple small diamonds, really are only saleable for the salvage value of the metal. Although small diamonds mounted in rings are possible to recycle, they are usually considerably less valuable on resale than people think they are. The solution is to talk to a pro who is specifically NOT going to be a bidder. If you prefer to do some legwork and don’t want to pay a fee, talk to several different bidders and compare notes.



Edited by denverappraiser
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Thanks Niel,


so the beep at least tells us that the diamonds are real. That the jeweller said the stones were cracked then confirms my suspicion about not everything being 100% right...


I'll take your advice and have it looked at by someone else as well. If they give the same low offer, I think I'll just try to sell it as the piece of jewellery it is on an auction site. Maybe someone will like it as a nice ring better than the jewellers does. I don't have any high hopes regarding the sales price though but if it is too low, maybe some female relative may want to use it.


Cheers, Jens.

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Good luck with it. Let us know how it goes.


It's entirely possible that the stones ARE chipped. It's also possible that the buyer is just making this up to drive down your price. The beep is simply no evidence either way. If he didn't look at them under magnification and they aren't obviously damaged by looking at them carefully yourself, I'm guessing he just made this up.



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