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Pre-1950's thickness of nacre?

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Old 08-04-2006, 02:13 PM
Taylor Taylor is offline
Ready For Grafting
 
Join Date: Jun 2006
Posts: 76
One of the pieces I inherited has 5 pearls around 6mm set on posts. I'm trying to determine if they are cultured or natural by looking down the drill hole with a 10X loop. If they are cultured they must have extremely thick nacre, like over half the pearl. I used the hot water method to remove one from its post and the only difference I see is a gradual yellowing and a dark brown smear in the center that may be glue. On other threads I have read that the old standard was .5mm. What does this mean? .5mm over all or as some ratio to total diameter? Was this true in the 20s and 30s as well? In the box with this piece was a scrap of paper stamped with the name and pre-1950 address of Raymond C. Yard and the handwrtitten words: 6 worn cultr prls. I have corresponded with the company and they do not think they made the piece, but could have replaced the pearls or identified them. However I don't even know if the paper goes with the piece or was just in the same box. So basically I'm trying to determine if these are cultured or natural. The insurance appraiser said they were natural but I wonder. Sorry to ask so many questions. Thank you.
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Old 08-04-2006, 02:21 PM
Zeide Erskine Zeide Erskine is offline
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Join Date: Nov 2005
Posts: 969
Hi Taylor.

If you cannot see a nucleus and there is a dark smear around the center, the probability for them to be naturals is about 90% and the chances for them being Mikimoto-patent tisssue-nucleated round akoyas 10%. The design of the piece has little to say about the age of natural pearls because they are typically reused over and over again for centuries.

Zeide
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