What kind of natural?

[MSC]

So this is the first pearl that I candled for that other thread, Dave thought the candling photos indicated a natural pearl. If so, what could it be? It is 7.6mm round, drilled through, and a cream color with a gold overtone (right word?) and lovely greenish orient.

 

[Lagoon Island Pearls]

It's so hard to say with any certainty, but let's examine what we know.

It's slightly off-round. It's aragonite gold with green overtones. It has a single nucleus. It has gas inclusions. It has a few bumps and pimples. It's highly nacreous. It's over-mature.

With those points, it's reasonable to presume it's not freshwater and not mytilid (mussel) from saltwater. The low volume of calcite can rule out heterodonta (clam)

If I had to guess, given the size, suggest it is Pinctada, either radiata (Gulf or Mediterranean) or maxima (South Sea). Not margarterifera (Tahitian) or fucata (akoya).

 

[MSC]

Dave, would figuring out if radiata or maxima require sending out to GIA?

 

[MSC]

would a color palette analysis tell the difference?

 

[Lagoon Island Pearls]

Dave, would figuring out if radiata or maxima require sending out to GIA?

I don't believe there is a chemical test which rules one or the other out. There is for freshwater/saltwater but levels of Manganese don't necessarily apply to species. They would xray it, then make visual comparisons to known exemplars. Blaire (Gemgeek) is better versed in GIA methodology than I am and perhaps she might weigh in on the question.

 

[MSC]

I'm looking in the book Pearls: A Natural History and the coloring looks a lot like the example pearl photo of radiata. Is radiata what is commonly called Arabian Gulf pearl or is that just a general lumping of all pearl spp that are harvested from the Gulf?

 

[Lagoon Island Pearls]

would a color palette analysis tell the difference?

Perhaps, but probably not. At first glance that would lean toward SS, but color is not always an exclusive factor. Even though we see patterns in known species, mollusks can produce natural pearls of any color.

Most often the donor/initiator determines color, not the recipient.

 

[MSC]

That does make sense to me, I would definitely like to hear what GemGeek thinks it could be as well.

 

[Lagoon Island Pearls]

I'm looking in the book Pearls: A Natural History and the coloring looks a lot like the example pearl photo of radiata. Is radiata what is commonly called Arabian Gulf pearl or is that just a general lumping of all pearl spp that are harvested from the Gulf?

Pinctada radiata, is commonly known as the Atlantic pearl oyster or the Gulf pearl oyster. It ranges across the entire Indo-Pacific, north to Japan and south to Australia. Incidentally, it is been classified an invasive species in the Mediterranean since it's introduction via the Suez Canal subsequent to it's construction.

 

[MSC]

ha, one man's treasure is another man's garbage!

 

[GemGeek]

Differentiating species is not always possible, but they are continuously searching for the keys to identification. You might enjoy this short report on what they have started research-wise to separate beadless Pinctada maximas from natural Pinctada maximas. There is a terrific video with Nicholas Sturman from the Bangkok lab about pearl identification, but it's in the 2013 continuing education part of the website and is not cleared for sharing.

http://www.gia.edu/gia-news-press/p...news&utm_medium=email&utm_campaign=2013-12-10

 

[MSC]

Thanks for the info! I'll settle with not knowing definitively for now and just make sometime cute with it

 

[Bodecia]

Hi Andrea, excelling candling photographs. Clever girl.

Will be doing some more candling tomorrow but still with my camera. This time with a light on. I have many pearls to check, natural and cultured. Microscope drivers will not open for my present microscope. I have been working many hours to get it to work but so far no good.

Might have to send it back as the CD I received with it was not usable.

Candling loads of pearls is seriously time consuming work and very hard on the eyes.

Dawn - Bodecia
http://www.ebay.com/sch/dawncee333/m.html
eBay Seller ID dawncee333 Natural pearl collector & seller. And all round pearl lover.

 

[Bodecia]

Meant to type "excellent" not excelling must be time I went to bed.

Dawn - Bodecia
http://www.ebay.com/sch/dawncee333/m.html
eBay Seller ID dawncee333 Natural pearl collector & seller. And all round pearl lover.

 

[MSC]

Dawn, I can't wait to see you candling photos! Dave's tip not to use modelling clay was a big help. And I liked the tissue box set up, I'm going to give that a try sometime in the near future
Here's what I ended up making with my natural pearl bead...
(bead cap is 22kt, bail is 18kt, and wire is oxidized silver. It is going to go on an emerald and 22kt gold necklace I made a while back. A bit of a franken-project but it's what I had on hand!)

 

[pattye]

Very creative and lovely! Eye catching!!

 

[MSC]

Thanks, Pattye!

 

[GemGeek]

I like the different colors of metal. Very cool.

 

[Lagoon Island Pearls]

You know what? The more I look at this pearl, the more I think we're mistaken.

I candled a few 20+ year old undrilled akoyas I had stashed away.





Other than the blemishes and gas inclusions, I'm seeing similar structures below the surface, but no deeper inclusions. There is a slight variation in the geometry of the stippled surface, but you can clearly see it's just below the surface.


I noticed you've since fashioned the pearl into a finished piece, but I might have been inclined to look down the holes a little closer.

One other concern, the layers of the nuclei. Look closely at the third image (note: edited from "first"), (albeit slight) the appears to be evidence of layering in the nuclei. In the last of the akoya images, they are seen

I have posted a few images of nuclei from American river mussels. Two species, washboard mussel with dark lines and pigtoe mussel with lighter lines.




One other point I should make. A single axis view is incomplete data. To be objective, it's important we obtain views from X, Y, and Z axis, systematically.

Here is the reason why, this image is the same washboard mussel in the first image of nuclei, just along a different axis. You can see the marked difference, that must be interpreted according to the other axis (plural).



Examine all of these images closely for a few minutes, then go back to the first page.

What do your eyes think?

 

[MSC]

Dave, when I go back to the first page I can see that downward striping pattern-ish in the first photo but not in the second. Does that indicate a cultured pearl or are you saying that you think it could be one spp vs another but natural?