Freshwater Pearls vs. Saltwater Pearls

The Real Differences:

Before one can cover the basic difference between freshwater pearls and saltwater pearls, you need to answer the question; what is the difference between natural pearls and cultured pearls?

Natural pearls and cultured pearls are both legitimate pearls. Unlike imitation pearls which are plastic or glass costume jewelry made to look like pearls, natural and cultured pearls are both real and there are no visible differences. The difference is in how they are created and their consequent prices.

Natural pearl forms when a mollusk protects itself from an irritation or foreign intrusion. Whether it is a small parasite or just a grain of unwanted sand, a mollusk will produce layers of protection called “nacre” around the intrusion. These layers build up and are what creates pearls with their beautiful luster.

Natural pearl in a mollusk

Cultured pearls basically form in the same way, except the irritation or intrusion is cultivated by humans placing something inside the shell. Cultured pearls are produced in large amount on pearl farms all over the world.


This process is commonly thought to have been developed by Mikimoto, world renowned entrepreneur and owner of one of the largest pearl companies named after him. However, the process was actually developed by British Biologist William Saville-Kent in Australia and brought to Japan by Tokichi Nishikawa and his friend. Nishikawa who was granted a patent in 1916 and eventually married the daughter of Mikimoto, allowing Mikimoto to use his son in law’s ground breaking technology to culture pearls.

The prices of natural pearls are more expensive than cultured pearls, because the supply is smaller and natural pearl finds are rare. Most pearls you find in stores nowadays are cultured and are sold by their millimeter size of the diameter. Unlike diamonds which can be cheaper if they are larger due to clarity, the bigger the pearl the more expensive.

Cultured pearls can be cultivated in freshwaters and saltwater areas. What’s the difference?

Freshwater pearls are cultured in mussels in freshwater environments like lakes or rivers. Majority of freshwater pearls are cultured in China.

Saltwater pearls are cultured in oysters grown in the ocean, where the waters are literally saltier. The most common types of saltwater pearls Akoya pearls found in Japan, South Sea pearls found in Australia and the Philippines and Tahitian pearls found in Tahiti or French Polynesia.

The mussels that grow freshwater pearls are enormously robust and are able to produce pearls in much harsher conditions than saltwater oysters. Another difference is that one freshwater mussel can produce up to 40 pearls in just one harvest where as saltwater oysters can produce just one at a time.

Freshwater Pearls inside an oyster shell at the Naga pearl farm at Koh Matsum

They also differ in what is inserted into the shell for the pearl to form through the nucleation of nacre.

Freshwater pearls are called “mantle nucleated.” This means a piece of another mussel is inserted into the culturing mussel in order to produce a solid pearl. Saltwater pearls are “bead nucleated” where a small round bead is inserted to stimulate nacre production, allowing for perfectly round classic pearls due to the shape of the round bead.

Most freshwater pearls range from 3 mm to 12 mm and are usually smaller then saltwater pearls.   Some saltwater pearls range from 8 to 18 mm or larger.

Saltwater pearls are generally round in shape because of bead nucleated and the shine is more brilliant than freshwater pearls. Freshwater pearls are mostly round to off round, or rice-shaped to baroque.

Perfectly round white akoya pearls Baroque freshwater pearls

Freshwater cultured pearls can be created in a spectrum of colors.  Many popular colors, white, pink, orange, and other pastels, can be achieved through natural means.    Saltwater water pearls, such as south sea pearls, have white, silver, cream and golden color.  The natural golden color is considered to be the rarest of all pearls.

Now that you have been educated in the differences between saltwater pearls and freshwater pearls feel free to browse our large selection of both type of pearls on

This entry was posted in General. Bookmark the permalink.