Cracking pearls

[JWei]

Some farmers in China are trying to use similar methods used in SSP.
I have asked one bead manufacture why he does not use the shells of saltwater oysters. They told me that those beads are not densely enough and easily to be broken up.
Josh, Is the shell of saltwater oysters not solid?

 

[CortezPearls]

The Freshwater technique involves a "mantle within mantle" procedure. That is: you make a little "taco" (or "quesadilla" if you prefer) of mantle tissue and you insert it within the mantle of the mussel.

You cannot graft saltwater oysters (Pteriidae) using this method, because the mantle of the pearly mussels is much thicker than that of the pearl oysters. We tried this technique many years ago...not much success there.

 

[CortezPearls]

Some farmers in China are trying to use similar methods used in SSP.
I have asked one bead manufacture why he does not use the shells of saltwater oysters. They told me that those beads are not densely enough and easily to be broken up.
Josh, Is the shell of saltwater oysters not solid?

The shell is solid...but either not thick enough to produce large nuclei or its thermal expansion coefficient is not close enough to that of nacre...thus pearls might explode when drilled.

 

[CortezPearls]

Yes, they can be used for nuclei. But the shells are too thin for anything larger than 6-7 mm, so unless you received a batch of small beads, it did not come from the Hyriopsis cumingii. The shell is mainly used for crafts, buttons, and of course all those products that have "pearl powder".

Mr. Shigeru Akamatsu had some nuclei that he was showing in Tucson. These were "reconstituted nuclei" (to give them a name): chinese mussel shells that had been glued toghether and then processed. The resulting nucleus was 16 mm in diameter, but you could see where the different shells were glued (due to the transparency of the glue AND the way the bands/lines met).

We would never buy nuclei like these...but if they are being manufactured, then it means someone is using them.

 

[Slraep]

Mr. Shigeru Akamatsu had some nuclei that he was showing in Tucson. These were "reconstituted nuclei" (to give them a name): chinese mussel shells that had been glued toghether and then processed. The resulting nucleus was 16 mm in diameter, but you could see where the different shells were glued (due to the transparency of the glue AND the way the bands/lines met).

We would never buy nuclei like these...but if they are being manufactured, then it means someone is using them.

Hola Douglas,

Those composite nuclei have been around for a little while. Some of them are B_I_G. No one wants to admit to using them. They are being sold! I suspect Philipine farmers of SSs, but who knows. I posted a company from Denmark that sells them.

Check out this thread:

Size of nucleus

Size of Nucleus

Hi everyone. I just had a question. How do you know what size a pearl's nucleus is? Does it matter if the pearl is 10 or 8mm? Do most cultured tahitian pearls get the same size nucleus, and if so what is that size? Thanks, -Steph

www.pearl-guide.com

Slraep

 

[Pearling Technologies]

BIG Nuclei

BIG Nuclei

Not sure if it is relevant but in this picture (very badly taken) there are 2 unpolished nuclei. The smaller one is 19mm.

 

[GemGeek]

Heavens! If the smaller one is 19mm, what is the size of the monster beside it?

 

[Slraep]

Last I heard, 22mm was the biggest.

Slraep

 

[Pearling Technologies]

the larger one measure about 32mm

 

[pearl guide]

Well! I hope you aren't just showing us that technology- I hope you will explain how you achieved that size-especially since the photo won't allow us to observe much detail....

Also, who would wear such a pearl- that is- who is the market for? Is there a pinctada that can take that size and be able to stay closed?!

 

[Slraep]

the larger one measure about 32mm

Is that a composite of two hemispheres?? If not then I will need some smelling salts.....

I can't imagine who, what, where, when and why, either. Oh yah, and how?

Slraep

 

[Josh]

I'm pretty sure those monster nucs would be from your favorite, Slraep: Tridacna Gigas. Some time ago George from Pearling Technologies said that this endangered species was still being used for nuclei. Fortunately in Tahiti anyway, it's been banned.
JWei, what you were told is silly. You can take a pinctada nuclei and drill it like swiss cheese and it still won't fall apart.

 

[Pearling Technologies]

I didn't mean to start a debte re the nuclei itself - it was just to show that larger nuclei can and have been produced. I also don't doubt that there would not be an animal that could take a nuclei so large let alone find someone willing enough to wear it if it was covered with nacre.

We used to routinely manufacture and sell nuclei up to about 6.3bu (about 19mm), mostly when wild shells were the mainstay of the Australian industry. Nowadays with hatchery production, sizes have been pegged back a little. Also, really big mussel shells are difficult to get and when you can get some, they are so old that the quality tends to be poor. This lead to cracking and breakages.

It doesn't take a really big nuclei to make a larger pearl when you consider a 5.3bu (16mm) bead could yield a pearl around 22mm.

The large nuclei in the picture (again sorry for the quality) is one piece and is a Bironite nuclei. We hand made the larger one although the smaller one (if you can call 19mm small) was made on our machines.

 

[Josh]

Hey George, a little controversy is OK. Eminem says we need a little anyway.
The biggest nuc I have in my possession is the 6.3 bu you gave me years ago. Still haven't found an oyster that wants it! Some day...

 

[CortezPearls]

Dear God!!! Any oyster would be "stuffed to death" with such a HUGE nucleus!!! Bironite intoxication happens (ask the oyster).

Kidding aside...I would like to Welcome George Ventouras to the Forum. It is good to have an old acquaintace join our group. We can all benefit from your knowledge and experience.

Welcome!