August 24:—SAN ANTONIO, TEXAS: Retail show; Southwest Gem and Mineral Society of San Antonio; Sat. 10-5
Welcome to the GemologyOnline.com Forum
A non-profit Forum for the exchange of gemological ideas
It is currently Tue Sep 17, 2019 2:45 am

All times are UTC - 4 hours




Post new topic Reply to topic  [ 3 posts ] 
Author Message
 Post subject: South Sea versus freshwater pearls
PostPosted: Mon Apr 15, 2019 12:32 pm 
Offline
Active Member

Joined: Mon Sep 11, 2006 7:11 am
Posts: 95
Location: Cape Town
I received a string of pearls for an appraisal and the client said they were sold as South Sea pearls for R200000 ($14250). The red flag went up due to the lustre and shape. The lustre appears to be too good for South Sea. They are a 'fat doughnut' shape and the size range is 10.50 - 11.00mm. I had them X-rayed but this was not conclusive as no nacre was clear enough to make a call. I then had a CT scan done on one of the pearls which indicates Freshwater. This will most probably end up in court, so I need to be absolutely sure of my facts.

I would appreciate any comments. Attached is a pic of the CT scan.


Attachments:
Image_4.jpg
Image_4.jpg [ 336.88 KiB | Viewed 1120 times ]
Top
 Profile  
Reply with quote  
 Post subject: Re: South Sea versus freshwater pearls
PostPosted: Thu Apr 18, 2019 4:43 pm 
Offline
Gold Member

Joined: Wed Jan 23, 2013 5:29 pm
Posts: 1012
Location: Paris
Perhaps, a picture of the necklace and pearls might help.

If the case needs to go to court, a lab report might be necessary, to determine if the pearls are nucleated, and the chemical composition of the nacre : freshwater (with manganese) or saltwater (without).


Top
 Profile  
Reply with quote  
 Post subject: Re: South Sea versus freshwater pearls
PostPosted: Fri Apr 19, 2019 10:48 am 
Offline
Valued Contributor

Joined: Mon Oct 17, 2005 11:10 am
Posts: 295
Location: Illinois
Whatever happened to the idea that there would be test strips to check for manganese?

_________________
I love the smell of Methylene Iodide in the morning...


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 3 posts ] 

All times are UTC - 4 hours


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
Gemology Style ported to phpBB3 by Christian Bullock