Can you tell the thickness of the nacre of the SS pearls?

[Twj]

Hi everybody,

I have several ss pearls here but I don't if they have thick or thin nacre. I don't know if you can tell the nacre of the pearls only by eyes. I hope I can get some ideas from the pearl professionals here. Thank you very much.

 

[Pearl Dreams]

You can't tell thickness of nacre of SSP and Tahitians just by looking at them.

 

[Twj]

Hi Pearl Dreams,

Thank you for telling me that. I am also wondering is luster related to nacre?

 

[Red]

You can't tell thickness of nacre of SSP and Tahitians just by looking at them.

It's my understanding that with experience you can detect very thin nacre areas by looking at them.

 

[pearlescence]

Nacre deposition depends very much on the individual mollusc. As we found out in March in Indonesia. All shells grafted with 6mm nucleus, pearls ranged from 8-12mm. grafted at same age, harvested together. Didn't depend on size of shell either. May depend on graft tissue or host tissue. not sure

 

[Twj]

Hi Red,
Would you be able to tell the thickness? Thanks a lot.

 

[Red]

Nope. Years ago I had purchased some SS pearls on Ebay, and was visiting with Sarah of Kojima Pearls, and she could spot the thin areas. Apparently, they "wink" when rolled around a bit.

 

[Pearl Dreams]

That is interesting. I knew akoyas with thin nacre areas can wink but would not have thought you would get the same effect with SSP, whose nacre is so much thicker.
Red, were those white SS? I don't think you could tell with Tahitians because of the nacre not being transparent.

Twj, there is a relationship between luster and nacre thickness in that pearls with great luster usually have thicker nacre, but thick nacre is no guarantee of luster. There is also the matter of how the crystals of aragonite are laid down.

 

[Red]

Red, were those white SS? I don't think you could tell with Tahitians because of the nacre not being transparent.

Yes, they were white and light golden SS pearls, not Tahitians.

 

[ericw]

Tjw, from my little experience, I would doubt that first pearl on the left and specially the one in the middle of first pic have regular nacre thickness. We can see, above a kind of darker colour wave of nacre, a clearer area which makes me think of the bead, seen by transparency.
But the only real ways to know thickness of nacre are X-ray testing, or examination of the hole, not possible in case of set pearls.... or to carve them
Pearl Dreams, In case of very thin nacre (about 0.1/0.2mm) on tahitian pearls, even black, you can see that because thin areas look more clear, and loose a great part of their lustre.

 

[pearlescence]

All pearls will blink if they haven't got any/enough nacre. It's just more likely that you will encounter akoyas which do because of how they are farmed

 

[ericw]

All pearls will blink if they haven't got any/enough nacre. It's just more likely that you will encounter akoyas which do because of how they are farmed

pearlescence, each kind of pearl has its own nacre optical properties. Akoya's don't work like south sea's. Akoya's nacre, but also many FWP's (except Edison!), seem less translucent than SSP or tahitian pearls nacre.

 

[Pearl Dreams]

Such an interesting discussion, but also dismaying...to think of possibly only 0.1 to 0.2mm of thickness in the nacre of SS or Tahitians, especially considering what they cost.

 

[pearlescence]

Blinking is caused by the bead being visible through a very thin layer of nacre. It isn't the properties of or the translucency of the nacre which cause blinking, but the depth.
It usually happens with just part of the whole pearl hence when the pearl strand is rolled some of the pearls look as if they are blinking at you

 

[ericw]

Such an interesting discussion, but also dismaying...to think of possibly only 0.1 to 0.2mm of thickness in the nacre of SS or Tahitians, especially considering what they cost.

Yes Pearl Dreams, it might be dismaying, but I am explaining how such a thin nacre would damage pearl's looking, in case of tahitians. I think tahitian pearls nacre become enough opaque up to 0.3mm thick, to avoid any view of the bead. But I can speak of these 0.1/0.2mm thick nacre effects, because I have seen them, carving new tahitian pearls I was talking about in an other thread. Unfortunatly
But I think the problem not so easy to spot in case of clear or white SSP.

 

[Pearl Dreams]

I suppose this is an argument in favor of being very careful about the vendors one buys from; a reputable one will be fussy about his or her suppliers.

 

[ericw]

Blinking is caused by the bead being visible through a very thin layer of nacre. It isn't the properties of or the translucency of the nacre which cause blinking, but the depth.
It usually happens with just part of the whole pearl hence when the pearl strand is rolled some of the pearls look as if they are blinking at you

So sorry, pearlescence, but I don't well understand. You are explaining that bead becomes visible through a very thin nacre layer, I agree you, and thus nacre is translucent. Now just I was pointed differences of this transparency between kinds of pearls.

 

[ericw]

I suppose this is an argument in favor of being very careful about the vendors one buys from; a reputable one will be fussy about his or her suppliers.

Pearl Dreams, it's the time to take care, sure!

 

[pearlescence]

Ah, now I understand what you were saying. But I still don't think the type of pearl makes much difference. very thin nacre is very thin nacre. And there is a big difference between translucent and transparent
I just met a strand of tahitians which had been dyed and coated. poor things

 

[ericw]

Ah, now I understand what you were saying. But I still don't think the type of pearl makes much difference. very thin nacre is very thin nacre. And there is a big difference between translucent and transparent
I just met a strand of tahitians which had been dyed and coated. poor things

Yes, pearlescence, I see what you mean about difference between translucent and transparent. I want to talk of translucency.
I assure you that there are truly differences between kinds of pearls nacre.
As I said, it's time to take care, specially with tahitian pearls. Did you imagine they have now the right to sell old pearls previously graded as production rejects and forbidden for sale before...?