Post subject: Re: Seperating Saltwater and Freshwater Pearls
Posted: Thu Aug 30, 2012 3:40 pm
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Joined: Sat Aug 25, 2012 3:45 am Posts: 134 Location: Kuala Lumpur, Malaysia
I am a pearl fan, and I have heard of this test before. But to do such a potentially aggressive test on any pearl.....I can't
In my opinion, as long as the pearl is of top condition (nice luster, nice surface condition, good color, nice shape with good size), I don't really care about whether it is from the sea or from the freshwater. Chinese freshwater pearls are really amazing lately! From the ulcerous looking seed pearls about 2 decades ago to the currently nice, huge, round or near round pearls that are as good as (or may be better than) certain saltwater pearls! Such freshwater pearls are made up of full nacre and are theoretically more durable than the cultured pearls with thin layer of nacre. And they are much cheaper !
Anyway, differentiation between the saltwater and freshwater origin may be very important for the pearl market (judged by the huge price difference).......then go ahead....
Nevertheless, I do notice that the "color play" of freshwater pearls is usually different from the seawater pearls. Freshwater pearls are usually made up of 100% nacre, resulting in very characteristic "rainbow color play effect" that you hardly see on seawater pearls....On the other hand, south sea pearls tend to show the soft, silky shine kinda luster. Even when the nacre is very thick, the "rainbow color play" is still very soft. And this soft glow of south sea pearls is seen in any color forms. I am not familiar with Akoya as for unknown reasons, I just not interested in Akoya...
Attached are some pictures form my collection of freshwater and south sea pearls. They may be helpful to highlight the optical differences between the pearls.
But again, a great pearl is a fabulous gem regardless of its origin....
Regards, WCLee
Attachments:
3 golden south seas.jpg [ 90.85 KiB | Viewed 6566 times ]
silver south sea.jpg [ 98.1 KiB | Viewed 6566 times ]
Post subject: Re: Seperating Saltwater and Freshwater Pearls
Posted: Thu Nov 29, 2012 10:29 am
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Joined: Sun Mar 08, 2009 2:16 pm Posts: 331
KS- This test would give you the same result for FWCP and FWNP. Xray fluorescence is used to reveal the chemistry on the outer parts of the pearl. What you need for distinguishing nat vs cultured is to view an X-ray photo to look at the inside. Is this the answer you were hunting?
Post subject: Re: Seperating Saltwater and Freshwater Pearls
Posted: Thu Nov 29, 2012 2:56 pm
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Joined: Wed Apr 18, 2007 4:38 am Posts: 142 Location: New Delhi,India
Bear Williams- SGL wrote:
KS- This test would give you the same result for FWCP and FWNP. Xray fluorescence is used to reveal the chemistry on the outer parts of the pearl. What you need for distinguishing nat vs cultured is to view an X-ray photo to look at the inside. Is this the answer you were hunting?
thanks for writing in,X-ray florescence does show a bright blue line when pearls are exposed to it. but similar results occur when salt water pearls are exposed to it though in salt water pearls case it don't happen with all of them. i wanted to know if magnesium test fits on both natural fresh water pearls and cultured fresh water pearls? do you mean x ray florescence shows high magnesium on pearl's surface?
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Post subject: Re: Seperating Saltwater and Freshwater Pearls
Posted: Thu Nov 29, 2012 3:36 pm
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Joined: Sun Mar 08, 2009 2:16 pm Posts: 331
Yes, the ED-XRF test would give you the same magnesium result for both FWCP and FW naturals. The Mn is just a trace element and exists throughout the nacre of all these FWP. XRF is pretty much a surface reading, and as you can imagine the calcium accounts for most %. off to catch a plane... bw
Post subject: Re: Seperating Saltwater and Freshwater Pearls
Posted: Sat Dec 01, 2012 10:59 pm
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Joined: Wed Jun 15, 2011 8:29 am Posts: 123 Location: London
That acid test got me thinking but about pearls I know next to nothing so I wonder if some experts could say if there's a procedure of restoring damaged pearls (if not damaged too deep of course). Theoretically you could remove damaged layers until you have undamaged one on top...
Post subject: Re: Seperating Saltwater and Freshwater Pearls
Posted: Sun Apr 14, 2013 8:38 pm
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Joined: Mon Oct 17, 2005 11:10 am Posts: 299 Location: Illinois
Spent an couple of days in Chicago at the Smart Shoe (Instore Magazine show). There was a gentlemen selling a gun type tester for scrapping precious metals in on of the tool booths. After watching it for a bit I went a borrowed a strand of salt water pearls and a strand of freshwater. The freshwater had 840ppm Manganese which was picked up in 25 seconds with no damage to the pearls. Unit was a bit pricey (17000.00) but I am guessing that besides giving you the exact content of your scrap, it would also be able to pick up the trace elements of black dyes in pearls and maybe even the agents they use to cost the bottom of some of the gemstones ( I know some have a gold content). http://www.oxford-instruments.com/produ ... 000-series Since I haven't seen any results on the separation proposed by Dr. Hanni, I assume that it doesn't work or is not feasible. Has anybody heard anything else since last fall?
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Post subject: Re: Seperating Saltwater and Freshwater Pearls
Posted: Wed Oct 26, 2016 9:47 pm
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Joined: Mon Oct 17, 2005 11:10 am Posts: 299 Location: Illinois
Been a while. Did anybody ever follow up on the test strips for Manganese? Freshwater pearls are getting better and harder to distinguish beaded material.
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