Caitlin,
An article appeared in the Summer 2008 issue of "Gems and Gemology", page 175, entitled "Pinctada Maxima Cultured Pearls Grown Beadless in the Mantle".
The article was discussed on this forum, also. I'm trying to find it.
Gail
P.S. Caitlin, maybe we'll see some in Tucson!