| There are no standards for nacre thickness in South Sea pearl production, at least not in the way there is in French Polynesia. But the nacre is typically very thick (2-4mm), at least when not dealing with indicator pearls, which I have not seen around in a while.
If the pearl is baroque it could definitely have thinner nacre on one side than the other, and thinner nacre does not mean the luster will always be bad (think akoya). This is a problem in Tahiti right now, with so much production going to waste because of thin areas (of baroques), even though the nacre is thick everywhere else around the pearl. |