Quote:
Originally Posted by effisk  Circled pearls are circled because they're turning in the pearl sac. At one point and for some reason the production of nacre slows down on parts of the the pearl sac's surface. Because the pearl is moving in the sac, the depression follows, thus creating circles. It's a theory that's still being discussed. I think it would be easy to verify it with marked nuclei and regular x-raying of the oysters/mussels.
I believe there are other theories. |
Many farmers use second and third-quality nuclei to save on expenses and the more irregular surfaces on some of these may also influence the development of circle pearls. Another theory is that disease or stress may cause faults in the pearl sac, contributing to the formation of circle pearls.