Freshwater pearls are mantle-tissue nucleated, whereas akoya pearls are bead-nucleated. Instead of inserting a mother-of-pearl bead and a piece of mantle tissue into the gonad of a freshwater mussel, as is the process with an akoya mollusk, only a piece of mantle-tissue is used, and this is inserted directly into the mantle tissue of the freshwater mollusk. The result is a pearl composed of solid nacre.
Although harvested freshwater pearls are solid nacre, and akoya pearls may only have .1 to 2mm of nacre over a bead-core, akoya pearls are generally considered more valuable.
Akoya pearls will average higher quality attributes than freshwater. Freshwater pearls are rarely round, whereas akoya pearls are generally round. Freshwater pearls do not typically have the sharp luster and high shine found in high grade akoya pearls, but can exhibit orient in their highest grades - something akoya pearls cannot.
If freshwater pearls are solid nacre, and high-grade rounds have orient, and the amazing roundness of freshadamas, shouldn't they be more valuable then their akoya counterparts?
Do you think that they are far superior? If you had a choice between the two, what would you pick and why?