Freshwater pearls are the most common type of pearl. As the name suggests they are grown in freshwater, usually in mussels that live in lakes and rivers. The process used to produce most freshwater pearls doesn’t require a shell nucleus, instead tissue grafting techniques are used.
Primary sources of freshwater cultured pearls are China, Japan and America. Commercial production of Freshwater pearls originated in Japan but factors such as pollution and viral disease have hampered their production. At present, China is a world leader in the production of freshwater pearls.
Freshwater pearls are cultured by tissue nucleation. This means that the mussel is pried open enough for a technician to insert a small piece of tissue into the mussel, this acts as an irritant and begins the production of nacre which starts the formation of the pearl, this is why it is rare to find a round Freshwater pearl.
It also means that a Freshwater pearl is virtually all nacre which gives a Freshwater pearl outstanding lustre and makes them great value for money. Freshwater pearls are quite durable and resist chipping, wear and degeneration. Culturing takes 2-7 years, with one mussel producing around 24-32 pearls.
Freshwater pearls come in an array of colours, this is a big advantage over saltwater varieties and it makes them highly versatile for jewellery. Natural colours include tones of white, pink, lavender, mauve and apricot.
Freshwater pearls are also commonly dyed or colour treated. Dyed colours include blue, black, purple, gold, coco, green and grey. It is important that you ask if the colour of your pearls are natural before you buy them.
It is very rare to find a round Freshwater pearl. Shapes are varied and include: near round, drop, button, baroque, keshi, coin, rice, potato and Biwa.
Sizes range from tiny seed pearls of 1.0mm – 2.0mm in diameter to 15.0mm in diameter in the rarest of cases.
|China and Japan
|Sankaku mussel (China), Ikecho mussel (Japan), Karasu mussel (China/Japan)
|Hyriopsis cumingii, Hyriopsis schlegeli, Cristaria plicata
|1.0mm – 13.0mm
|White, pink, lavender, mauve, peach, apricot
|Near round, drop, button, baroque, keshi, coin, rice, potato and Biwa