Thanks for that , very helpful , I’ve had it for 5 years , it was cleaned last year but was already like that , just thought it was an unusual colourOK! This is my gut feeling. That used to be a cultured pearl, but it's either been through the digestive system of an animal, or submerged in vinegar or the wrong sort of cleaning solution. It looks like all the pearl nacre has been eaten off and all that's left is the shell nucleus, because it's "cut in" from the edge of the gold mounting and not flush with the gold mounting. That pearl is not coming back from the dead. If you like the setting, replace the pearl. At this point, there's no telling what kind of pearl that was because all the nacre is gone.
From Fred Ward's Pearl book.
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Thanks for that , very helpful , I’ve had it for 5 years , it was cleaned last year but was already like that , just thought it was an unusual colourmore fool me , glad i never paid much , thank you anyway*
I think it’s been rubbed on skin as it’s the back side of it that lost its luster the rest seems okI got it as a present, it was bought at an antique market