mabe pearls from sumbawa/indonesia

[la_corsetiere]

I saw these listed by Augustus-company on ebay, from whom I've purchased before. They are said to be from the penguin wing oyster. I asked whether or not the color was natural - this was the response:
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"When these Mabe pearls are cultured a nucleus is inserted against the side of the oyster. When the nucleus used is white or a light color the nacre of the Mabe develops in light colors from white to gold and mauve. When a black or blue nucleus is inserted the nacre of the Mabe develops in shades from blue to purple.

This way the color is influenced. It is a kind or color treatment, but there is no dye involved.

I also just found at the farm pink Mabe for which they use a red nucleus.

It is very mysterious how the oyster reacts to different colors of the nucleus.
There are also Mabe pearls available which are dyed, but the blue looks very different and artificial"
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So, does this sound accurate? I've never heard of using different colored nucleus to influence the pearl color...

Sheri

[J Marcus]

Although I cannot say for sure without inspecting and, perhaps, taking one apart, I have a feeling that the way that the color of the pearl is influenced by the nucleus is by transmitted light reflecting off of the nucleus and back through the nacre. For this to be very pronounced, I think that the nacre would have to be rather thin--perhaps thin enough to negatively affect the durability of the mabe. I would be suspicious of how much everyday wear they could sustain without wearing through or cracking the nacre. One of the characteristics that separates the quality of cultured pearls is thickness of nacre. About the only other way for the nucleus to affect the color that a cultured pearl appears would be if it contained a soluble dye that would bleed out into the nacre. The color of the nacre of all of the shells and pearls that I have seen from Pteria Penguin, which is often used to form Mabe's has varied from quite transparent with just a bit of milkiness through a range of white through tan, to a bronzy brown.

[GemGeek]

Marcus is right -- they are thin enough to transmit the color of the implant. If you remove the backing, the color of the nacre is the same as the inside of the shell. Probably not a good choice for rings...

[la_corsetiere]

Thanks for your feedback. I agree - not a good choice for rings...which was what I was thinking of doing with these pearls. You have saved me!

Sheri

[Pearling Technologies]

I would doubt that the colour of the nucleus affects the actual colour of the nacre laid down. We have processed mabe ex Maxima shell and have dissected them also from other suppliers. As some of the caps can be quite thin, especially after cleaning (at times grinding to get the muck off), they are often painted. This 'paint' can affect the undertones of the colour seen on the surface. The resins that are used to fill the mabe cap before backing can also influence the tones of the surface. These tone variations would only be marginal and would not change the colour of the pearl itself to a large degree.

[la_corsetiere]

The resins that are used to fill the mabe cap before backing can also influence the tones of the surface. These tone variations would only be marginal and would not change the colour of the pearl itself to a large degree.

Thanks for your input - I bet this is what is really behind the seller's explanation - it's not actually the nucleus that affects the color, but the resin filler. This is not TOO far removed from their explanation. I've had good luck with the vendor in the past - bought a lovely horn abalone pearl a while back - so I'd hate to think they were outright lying! Could well be that they were misinformed.

Sheri (who is trying to squelch the cynical and see the happy niceness of the world.....)

[CortezPearls]

That is the reason why Mabe producers should stick to a translucent or white colored resin. If your coating is thin and you have a colored resin then you get a "colorful" pearl but they are cheating.