A freshwater pearl is primarily cultured in a non-saline environment and is specifically produced by freshwater mussels. China is currently considered the exclusive producer of freshwater pearls, but is also produced in limited quantities in the United States and Japan. Ever since the 13th century, China has already been in the industry of producing freshwater pearls and has already taken its place as the leader of the pearl trade. The US was also previously a big player in the pearl industry, but the increased level of pollution and unregulated harvesting contributed to a major decline to mussel population.

Japan once had a very colourful history in the freshwater pearl business, first utilizing Lake Biwa as breeding grounds for pearl-producing mollusks known as the Biwa pearly mussel.  Pollution in this lake caused a major impact in the life of mussels, ultimately putting an end to the Japan’s pearl farming industry in the year 1970. Not very long after that, the Japanese were still able to temporarily revive their pearl farming industry, making use of Lake Kasumigaura to produce pearls from a hybrid mussel through bead nucleation. This one also ended up being decommissioned due to pollution.

One very distinguishing characteristic that separates a freshwater pearl from its saltwater counterpart is that it doesn’t possess the same level of luster and shine as compared to the well-known Akoya pearls, and they are also not as round. They are also much more affordable and more durable because of their naturally solid nacre – very resistant to chipping, wear and tear. Fashion designers and young women alike favor this type of pearl more because of the myriad of shapes and colors available, combined with their affordability and durability which makes them perfect for everyday use too.

Unlike cultured pearls which are formed by bead nucleation, a freshwater pearl is formed through a process known as grafting. Grafting is done by acquiring a strip of tissue from the mantle of a donor mussel, which are then cut into 3mm squares and inserted into the fleshy mantle tissue of a properly aged mussel (6-12 months) through a small incision. The grafted mussels are introduced back into the freshwater and are taken care of for a period of 2-6 years, resulting to pearls that are thick in nacre but are not perfectly round due to the absence of the bead nucleus which guides the pearl growth.

Despite the imperfections and other issues of the freshwater pearl, it is now considered to be a lot better in terms of quality because of the major improvements implemented in its production. Previously, China was producing low-quality pearls known as “Rice Krispie Pearls” (from cockscomb pearl mussels) due to the unusually high volume produced for each grafting process (up to 50 times per mussel), but eventually shifted to the triangle shell mussel in 1990. Grafting for this mussel is now lowered to 12-16 grafts, which also yielded lower amount of pearls (24-32), but of superior grade.