Cultured freshwater pearls are pearls that are farmed and created using freshwater mussels at pearl farms in Japan, Australia, Indonesia, China and many more locations. Natural/wild pearls are typically found by shellfish harvesters purely by accident. You might have to open 10,000 oysters to find a single decent quality natural pearl.
. The quality of cultured freshwater pearls is evaluated through a grading system of a series of A values, based on lustre, shape, surface, colour and matching.