Candled Natural Pearls

[GemGeek]

I don't think GIA has used much in the way of x-ray film for a long time. They had digital micro x-radiography before they went to the digital real time CT scanning. Digital micro x-radiography is nothing like ordinary x-rays with film - then ramp that up exponentially with the CT - Whoop!

Love the music, Caitlin!

 

[Lagoon Island Pearls]

Is the post where Blair refers to 'windows on the past' in this thread? I am not sure what she meant so I am wondering. Is it possible to ad a link?.

I don't recall that thread. Got me curious too. Blaire?

I may not understand some of what you do. Is any of this farmed pearl void evidence from previous culturing attempts by past farmers in your area up there?

No. There was only one other pearl farmer on this coast. Dr. Peter Fankboner. I know you are aware of his work with abalone. He did work in other countries, but to my knowledge, voids were not discussed or described in any of his papers.

I have only read this paper and it does not definitively say the pearls with voids are proven to have been farmed, or did I miss that part?

Any non beaded pearls may or may not have voids. Those with voids can be broken into categories. By a stroke of luck, Sophie posted a couple of important images. In natural pearls, the initiating event often persists, hence displaying signatures (shadows) in successive layers over a few seasons. You'll notice the nuclei of the purported cultured pearls are contained within the initial ring at onset. Then clean layers atop, after all a cultured pearl graft tends to heal quickly, then produces gem quality nacre at the surfaces of each layer.

Is it 100% in every case?, definitely not, or at least in my opinion. There are many natural pearl nuclei contained within the initial ring, but the incidence of NBCP presenting with initiating effects outside the first ring is very low. I believe the author intended the data to be generally acceptable, not necessarily exact.

 

[GemGeek]

I think what Dave meant about windows was that I had said in a couple of different ways that his pearls have much greater translucency than most of the pearls that we are likely to encounter. That translucency has given him a leg up on seeing the different "events" that show up concentrically as the pearl grows - spots - conchiolin - cracks - stuff - like rings on a tree.

 

[FrenchPearl]

I updated my earlier post and added a video that might interest you all. It shows how rendering software created for the video game industry can be applied to the human body scans (I believe based on CT scans, but should also work for digital xrays scans).
Now imagine a natural pearl instead of a human body..... Could we see the potential critters in 3D ?... how cool would that be to be able to virtually peel a pearl layer by layer !

GG : Do you know if the GIA is working with such software ? If not, and if you work with / for the GIA (?) I'd be happy to connect them (the company has a US HQ in Seattle) ;-). And thanks for the link of the Cheapside treasure. I just love treasure stories!

Dave: "By a stroke of luck"--> beginner luck ?

Caitlin: in the 2010 GIA tech note, there are some images / scans of beaded pearls . I'll add them to this thread tomorrow for visual comparison.

 

[Lagoon Island Pearls]

Dave: "By a stroke of luck"--> beginner luck ?

Lucky for me. You saved me the task of posting those pictures to answer Caitlin's question.

 

[FrenchPearl]

Oh, I get what you mean now.. I was a little confused

 

[GemGeek]

If only I could show you video of the CT scanning of a pearl. They go "through" the pearl in 3D, so that you can really see the character of the void or center.

 

[Caitlin]

I think what Dave meant about windows was that I had said in a couple of different ways that his pearls have much greater translucency than most of the pearls that we are likely to encounter. That translucency has given him a leg up on seeing the different "events" that show up concentrically as the pearl grows - spots - conchiolin - cracks - stuff - like rings on a tree.

Thanks fantastic metaphor!!!

 

[Caitlin]

Thanks GG! I really did not know they let people read their papers in pdf- that is really generous. Also I am so happy I can keep track of their findings on the huge hoard of natural pearls that Paspaley recently helped them find and harvest. Paspaley used their submarine! Ordinarily I would get a bit mockish at Paspaley having a submarine, if they use it for financial or political furtherance, but when they use it to further scientific research, especially research that will be available for the public to read for free. I just send them a HUGE hug and thank you for that! Mwaah Paspaley.

 

[Bodecia]

Hi All,

Barry and I have been candling for two days and we are both exhausted. Candled 52 pearls which of most I expected to be cultured but a few I thought just might be naturals. Taken well over 1000 photos and I have been going through them all. Need a holiday - help.

Why I started on this lot was because I wanted to used them in a design if cultured but I had the impression they were a mixed lot. Wish now I had just put them all away until later. I put each one in a tiny plastic bag with a number so I could keep track of what I was doing.

Will now add some photos for dissection - hah. When I have the energy again I will be candling pearls I do believe are naturals. So much more fun. I do have one pearl 7.6mm to double check by candling for pearlvl1 and then I am going to design and have some fun. When going through this lot of 52 pearls and even Barry started to recognise different features in the pearls such as banding and those that appeared to have natural features or those that were obviously cultured.

The last photo may show what is a bead but I am not sure. It is an interesting pearl with loads of features and taken from different directions.

Photos taken with a camera. I don't think I will have my working microscope until around Xmas.

Starting with Number 8 Pearl.

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

 

[Bodecia]

One more thing. I advise anyone who plans to candle pearls with drill holes to clean the drill holes thoroughly before taking photos. I cleaned these but did not get the drill holes really clean therefore the dirt left in them is messing with indications.

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

 

[Bodecia]

This is Pearl Number 50 - one I also found interesting even if I could not say natural or cultured. Each pearl has had a lot of photos taken of it and I ended up with 3 containers. One had all those I could identify as cultured with assurance. Another had those that I wanted more photos of to decide and the third that I thought looked like they just maybe naturals. These that I am adding including number 8 and number 50 are from that last lot.

What I want to do is either put them away for further study and my microscope or put them in the cultured box so I can design with them.

The necklace I bought them on was the one with the beautiful silver and paste pendant from around the early 1900s. When I bought it the pearls were sold as naturals but they arrived I thought not likely and then inspected them. Three or more had large drill holes and in two of those I could see a bead. So cultured. But on further inspection after cleaning and breaking the necklace I thought the other one that had a large drill hole looked like it might be a possible natural. Some just looked different so I thought to candle those and then it grew to taking candle photos of them all, even the ones I could see a bead in. This is just for background on them. Even before buying them I did not believe for one minute that the necklace was all original. I just took a punt.

Later if wanted I can add photos that show definite signs of culturing such as visible beads, banding etc.

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

 

[Bodecia]

Number 50 also had what may be banding in colours i.e. the pink, purple and green. It also shows a possible bead in a some photos so probably is a cultured pearl but I am adding them as I see ones with what I think are features of interest. Opinions gratefully accepted regardless. Once again photos taken from different angles. By giving them numbers I think for anyone that is interested it will be easier to look up the whys of the pearl.

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

 

[GemGeek]

You did a lot of work -understatement! You have probably learned a lot more about pearls by seeing so many. I like the the teamwork aspect!

 

[Bodecia]

Thanks GemGeek aka Blaire,

Barry does help me and after I get a pearl necklace ready for knotting he takes over. Almost all the time we restring any pearl necklaces to be listed for sale. Old necklaces just need it. Dirty silk and pearls with stretched silk I do not find appealing enough to list. I also remove any dead or pearls which have been abused with perfume etc.

So we do work together. Barry took the photos of all this lot of pearls and I went through them. He has been taking around 500 photos a day. He doesn't want to look at another pearl for a while I don't blame him but when I was going through them on the computer he couldn't help watching and asked me to stop examine the photos for a while.

The more we looked the more we patterns we started to see. I am still going through the photos just can't stop myself.


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

 

[Lagoon Island Pearls]

Wow Dawn, you've been busy!

Both appear beaded. I'm not seeing pronounced contrasts in the layers of the bead similar to washboard mussel, but I am seeing features of pigtoe mussel nuclei. Several of those beads in my batch have patches of calcite similar to ones shown in these images. I'll show you a comparison next week, when I get back to my stash of nuclei in the lab on Clayoquot Island. I'll candle some.

Another observation, similar to one I made on Andrea's pearl. It's more apparent on one, less on the other, but both present with color shifted patches and stippling just below the surface at equal depth. I don't see any deep inclusions. I don't see any initiating events other than what appears to be graft tissue in the lobe of the teardrop pearl. Again, near the surface...not deep in the middle.

Likewise, I see a contrasted ring near each hole. A drilled natural pearl would not present in this manner.

To expand a little on these views, let's discuss conchiolin for a moment. Conchiolin is substance created by mollusks which contains proteins and sugars. It's laid up by epithelial cells adjacent to the cells that lay up aragonite. In juvenile growth, it's present in greater volume than mature layers. Remember we discussed overmaturity a while ago? Overmature pearls have very thin layers of protein while aragonite and calcite predominate. When we have a view of cross sections, dark contrasts indicate protein content. If there is a ring around the hole, that ascertains the pearl is cultured, because the higher concentration of conchiolin is just below the surface, not at the center of the nucleus.

Again, as I told Andrea, I don't enjoy being spoil-sport, but this is a learning experience and we've advanced a method that helps all of us better understand the differences in pearl origin.

 

[Lagoon Island Pearls]

Inside the red line, is a patch of calcite on the bead.

 

[MSC]

Dave, I think it is very very helpful that you circled the area of note and explained what it is. I think diagrams like that are helpful for visual learners like myself!

 

[Lagoon Island Pearls]

I agree and will do that often as possible.

 

[FrenchPearl]

I love, love, love this thread ! The candling, the comparison with xrays, the methodology, and the group spirit of giving and contributing to spread more knowledge.
I' m so frustrated to not be able to take meaningful pictures of my pearls ... Meanwhile, i found a portable candling set up while I was stuck in traffic... My iphone 5 flash light ! The size of the light beam is perfect for pearl 6 mm and above !