Tom Stern's natural pearls

[Caitlin]

Posting on behalf of Tom:

This article appeared in a learned scientific journal yesterday. The mention of pearl structure is in the mid-portion and explains the characteristics of pearls at the level below discussions of conchiolin and aragonite, etc. It seems appropriate for a pearl experts' website, and if you agree, please post.
Tom

http://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networks

Colloidal crystals make better neural networkshttp://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networkshttp://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networkshttp://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networkshttp://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networkshttp://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networkshttp://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networks

By Adam Stevensonhttp://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networkshttp://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networkshttp://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networkshttp://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networks | Published: July 28, 2008 - 01:37PM CT
In order to understand the human nervous system, it is essential to understand the growth and structure of three-dimensional neural networks. However, most neural network studies have been limited to two dimensions or unrealistic representations in three dimensions. In a recent Nature Methods article, researchers from University of California Berkeley and Lawrence Berkeley National Lab demonstrate a method for producing three-dimensional neural networks based on templates made with colloidal crystals.
A colloidal crystalhttp://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networkshttp://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networkshttp://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networkshttp://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networks is a highly ordered array of particles with diameters between 10 nanometers and 100 micrometers. It has been shown that particle packing and crystal structurehttp://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networkshttp://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networkshttp://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networkshttp://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networks in these substances is tightly controlled by particle size, chemistry, and shape. Over the past decade, colloidal crystalshttp://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networkshttp://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networkshttp://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networkshttp://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networks have been heavily studied because their unique optical properties allow them to behave as waveguides and may enable optical computing devices. A common example of natural colloidal crystals is a pearl—pearls get their unique appearance from their underlying colloidal crystalline structure.
In this paper, the authors coated colloidal borosilicate spheres with poly(L-liysine) to promote cell adhesion and then attached rat hippocampal neuron cultures to the spheres. The glass spheres were then placed on top of two dimensional neural network samples obtained from embryonic rats. After three weeks of culturing , the result was a three-dimensional neural network with a realistic neuron density. The authors also found that they could influence and guide network formation by incorporating defects such as larger spheres into the colloidal crystal.
To study the networks, the nerve cells were stained with fluorescent photoswitching compounds and imaged with confocal fluorescence microscopy. This resulted in stunningly detailed images of three dimensional neural networks that allowed the authors to selectively stimulate neurons and record neural activity throughout the network. In this way, the researchers were able to determine connectivity between various layers of the colloidal crystal and study how this connectivity is controlled by factors such as chemistry and electrical history.
Given the chemical and morphological flexibility of colloidal crystals, this work should enable a host of future experiments in neural networks that range from studies of network formation and connectivity to neuron-targeting medications. An enhanced understanding of three-dimensional neural networks could also have implications for future computer processor architectures, network protocols, and other information technology applications.
Nature Methods DOI: 10.1038/nmeth1236 http://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networkshttp://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networkshttp://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networkshttp://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networks

http://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networkshttp://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networkshttp://arstechnica.com/journals/sci...olloidal-crystals-make-better-neural-networks

 

[SteveM]

The mention of pearl structure is in the mid-portion and explains the characteristics of pearls at the level below discussions of conchiolin and aragonite, etc.

Seems like a higher level to me?

From the linked articles, 'Photonic opals' and 'inverse opaline materials' seem like terms that should be discussed and understood here, and I for one would encourage any current or new forum contributor with appropriate background to guide us through this morass, in lay terms.

 

[GemGeek]

That's absolutely fascinating and very appropriate!

 

[DrTKStern]

Tom Stern's natural pearl blog

Tom Stern's natural pearl blog

To promote awareness of the natural pearl trading activities worldwide, I have established a blog. Please submit any information you have on recent offers and sales so I can post the information. Beginning in 2002, a tremendous escalation of natural pearl prices has taken place, as the elite collectors and buyers come to grips with the reality that in a few years, pollution of the seas will render natural pearls either extinct or of low quality. Already, individual buyers in the Gulf have accumulated collections in excess of 700,000 pearls.

http://naturalpearlbusiness.blogspot.com

Tom Stern,MD

 

[Caitlin]

You are on a roll! You bought in at just the right time. Good luck! Are you going to the pearl sale?

I can hardly wait to see what happens at that auction. I guess that means my little collection of very,very round Bahraini pearls is going up in value too!

Are you going to Dubai?

 

[aggiep]

I just spent a bit of time plowing through this full thread. Tom are you going to be Tucson again this year? If so what time period and which show? I'm feeling an Eegee's attack happening about Feb.

 

[Caitlin]

Do they only have Eegee's in Tucson? If so, I hope you and others will come here for some-and the pearls of course!

 

[DrTKStern]

You are on a roll! You bought in at just the right time. Good luck! Are you going to the pearl sale?

I can hardly wait to see what happens at that auction. I guess that means my little collection of very,very round Bahraini pearls is going up in value too!

Are you going to Dubai?

Hi,

I'm going to Dubai, Mumbai, and London in about 2 weeks. Main reports will be on blogspot

http://naturalpearlbusiness.blogspot.com

Yes, your Bahraini pearls are going up, up, up in value. They were beautiful.

Regards,
Tom

 

[J Marcus]

Hi Tom,

Great idea! You've got a lot of ground to cover though, I think. (...or maybe that should be water?) Looking over your blog, I couldn't figure out how to contact you for items to post. Maybe that can be made a little clearer? Good luck with this.

----------------------
Marc
http:www.flyrodjewelry.com/home.html

 

[Slraep]

Don't know if the natural pearl's value is really on the rise.

And according to this article, and some recent statistics on luxury items, it's not.

http://www.wealth-bulletin.com/portfolio/products-and-strategies/content/2451688251/

"Billionaire's pearl necklace halves in value when US billionaire Harold Dodge paid a record $825,000 (€567,000) for a pearl necklace in 1920, he can scarcely have thought it would halve in value 88 years later."............

Slraep

 

[Valeria101]

Auction records are no secret, but the fate of every pearl remains anybody's guess... that's about the only sure thing I can think of on the matter. The rest is just (delightful) guesswork.

And since it is fun, here's the guess: although fantastic, the necklace of a myriad of smaller pearls is not similar to the pearl items that did fetch seven figures in the past 15-18 months (all large pearls of classic shapes, some with certain provenance) although that ain't saying much, considering what those were! It is tempting to think that one tremendous price point creates an instant continuum of possibilities behind it, even 'tempting' in a profoundly, generally human way, but even so ... well... dunno if that can be taken for granted of all things. The little leap of faith required is being plastered over as we read: simply stating that the poor necklace is going for peanuts amounts to calling 500k a 'bargain' (not that the sum would not be exactly that in many varied contexts, but the number does reach high among all jewelry prices overall). This sounds like straight second-wave advertising: why else would such a piece o jewelry even hit the news since the pool of buyers is not exactly large enough to warrant mass-media approach? I can remember at least one other leading item in a recent Bonham's US jewelry auction that went through similar treatment... Also, if attaching a portrait of Catharine the Great to a necklace doesn't amount to pedigree (wasn't that sort of ornament typical for royal presentation items instead?), the Dodge ownership just might; yesterday is history also.

Anyway... guessing (for the record)... it will be fun to watch what happens with the sale

 

[DrTKStern]

Dodge Necklace

Dodge Necklace

Many years ago, this necklace was split into 3 strands as inheritance passed to Dodge children. Now heirs have elected to recombine them into the original piece for sale. The market for high end pearls in America is weak due to the dollar's decline, while the markets in Russia, China, and the Gulf are booming. Bonham's in Los Angeles is, I believe, the source of the necklace, which will be marketed world-wide by them. As yet, I've not personally inspected the item, but will report if I have the opportunity and decide to bid. On October 13,14,15 there will be a gem and pearl extravaganza in Dubai. For details, you can check my blog in a couple of days.

Best regards,
Tom Stern,MD

 

[SteveM]

As an owner of natural pearl pieces of some significance and with a more than casual interest in their valuation, I can only hope that value is rising. But it appears to me that naturals (exotic and otherwise) are coming out of the woodwork of late and it is hard to believe that supply does not exceed demand. Historical value would be a parallel but unrelated issue.

 

[DrTKStern]

As an owner of natural pearl pieces of some significance and with a more than casual interest in their valuation, I can only hope that value is rising. But it appears to me that naturals (exotic and otherwise) are coming out of the woodwork of late and it is hard to believe that supply does not exceed demand. Historical value would be a parallel but unrelated issue.

Hi,

Right now is a great time for you to test the market with a significant piece, though the USA would not maximize value. You might want to place something with Sotheby's or Christie's for a Gulf or Hong Kong auction, set your reserve at your comfort level, and see if you receive a VERY pleasant surprise when the bidding is over.

Just a thought. I saw a necklace today that indeed sold for $300,000, with the largest natural at 10mm, and no diamonds, rubies, etc. Very nice piece.

Tom

 

[Slraep]

I think this is a more detailed description of the Dodge pearls in question:

"A mysterious pearl necklace that may have once belonged to Catherine the Great, Empress of Russia, will be auctioned off by Bonhams in New York in December. Automotive billionaire Horace Elgin Dodge purchased the necklace from Cartier in Paris in 1920 for his wife Anna Thomson Dodge at the astonishing price of $825,000 - about $8 million in today's dollars.".....

http://www.luxist.com/2008/09/08/mysterious-cartier-pearls-linked-to-catherine-the-great/

Slraep

 

[DrTKStern]

Pearl and Colored Gem Show

Pearl and Colored Gem Show

ICA (I think it stands for International Colored Gem Association of New York), and the Dubai Pearl Exchange will hold a pearl and colored gem show in Dubai on October13,14,15. The first two days are open only to pearl traders, and the last day is open to the public.

 

[Mikeyy]

Sorry, I went right by that post. Good luck

 

[pattye]

Hafta say, really love the Dodge pearls, the photos are better than lots we've seen. And the pearls look very lustrous plus good sized too-------------

 

[Mikeyy]

Hafta say, really love the Dodge pearls, the photos are better than lots we've seen. And the pearls look very lustrous plus good sized too-------------

So they didn't sell enough Dodges and now they are selling their treasures. Sad.

 

[DrTKStern]

Rare natural pearl

Rare natural pearl

This pearl is the second-rarest type known. It is NOT the pearl I showed earlier, which was a marine gastropod. For fun, I'll let everyone take guesses what marine creature created this GIA certified object.

Tom Stern, MD
Member, Dubai Pearl Exchange