Freshwater Pearls Value, Price, and Jewelry Information

14k gold flower brooch with freshwater pearl petals and diamond accents. Photo courtesy of liveauctioneers.com and Ascendant Auction Galleries.

Freshwater Pearl

Like their marine cousins, many freshwater mollusks can produce pearls. However, this rarely occurs in nature. Today, the majority of pearls on the market are actually cultured freshwater pearls, and they make very popular and affordable jewelry stones.

Freshwater Pearl Value

For detailed information on quality factors for freshwater pearls, consult our pearl buying guide as well as our cultured pearl appraisal guide.

AGTA Spectrum award-winning necklace

This chevron pendant/necklace with freshwater pearls, rubies, emeralds, and sapphires in 14k yellow gold won the 1985 AGTA Spectrum Jewelry Design Competition. Photo © Joel E. Arem, PhD, FGA. Used with permission.

The International Gem Society (IGS) has a list of businesses offering gemstone appraisal services.

Pearls via Gem Price Guide

Prices of pearls are based on several quality factors. The values provided in this guide are for round cultured pearls. Baroque pearls are about 25-35% the cost of round pearls. Natural pearls are extremely rare, and largely limited to auction and collector’s markets. These can be worth 10 to 20 times an equivalent Akoya cultured pearl.
Akoya Pearls with White Body Color
Matching Pair
Size (mm) Top Luster High Luster
6 - 6.5 - -
6.5 - 7 - -
7 - 7.5 - -
7.5 - 8 - -
8 - 8.5 - -
8.5 - 9 - -
9 - 9.5 - -
Single Pearl
Size (mm) Top Luster High Luster
6 - 6.5 - -
6.5 - 7 - -
7 - 7.50 - -
7.5 - 8 - -
8 - 8.5 - -
8.5 - 9 - -
9 - 9.5 - -
Freshwater Pearls with White Body Color
Matching Pair
Size (mm) Top Luster High Luster
6 - 7 - -
7 - 8 - -
8 - 9 - -
9 - 10 - -
10 - 11 - -
Single Pearl
Size (mm) Top Luster High Luster
6 - 7 - -
7 - 8 - -
8 - 9 - -
9 - 10 - -
10 - 11 - -
South Sea Pearls
Matching Pair
Size (mm) High Luster, White High Luster, Golden
8 - 9 - -
9 - 10 - -
10 - 11 - -
11 - 12 - -
12 - 13 - -
13 - 14 - -
Single Pearl
Size (mm) High Luster, White High Luster, Golden
8 - 9 - -
9 - 10 - -
10 - 11 - -
11 - 12 - -
12 - 13 - -
13 - 14 - -
Tahitian Pearls with Black Body Color
Matching Pair
Size (mm) Top Luster High Luster
8 - 9 - -
9 - 10 - -
10 - 11 - -
11 - 12 - -
12 - 13 - -
Single Pearl
Size (mm) Top Luster High Luster
8 - 9 - -
9 - 10 - -
10 - 11 - -
11 - 12 - -
12 - 13 - -

Calcareous Concretions / Non-Nacreous Pearls Value via Gem Price Guide

Conch Pearls
All sizes
to ,000/ct
Tridacna Pearls
All Sizes
- / ct
Melo Pearls
All Sizes
- / ct

Freshwater Pearl Information

Data Value
Name Freshwater Pearl
Is a Variety of Pearl
Colors White to cream, orange, purple, tan, gray, pink; rare untreated colors include bronze and green.
Crystallography Amorphous. (Aragonite in nacre is orthorhombic).
Refractive Index 1.53-1.69
Luster Pearly, dull
Polish Luster Dull to nearly metallic
Fracture Luster Dull to pearly
Hardness 2.5-4.5
Wearability Good to Poor
Fracture Uneven
Specific Gravity 2.6-2.78. Cultured pearls may range from 2.72-2.78. This is not a diagnostic test.
Birefringence None
Cleavage None
Luminescence Freshwater pearls always glow yellowish white in X-rays.
Luminescence Present Yes
Luminescence Type X-ray Colors
Enhancements Bleaching (very common), dyeing, irradiation.
Typical Treatments Bleaching, Dyeing, Irradiation, Surface Coating
Transparency Opaque
Phenomena Orient
Birthstone June
Pleochroism

None

Optics

N = 1.53-1.69, but not observed; usually vague shadow edge in this range.

yellow gold and pearl ring

14k yellow gold ring with a freshwater pearl, 9.3 mm. Photo courtesy of liveauctioneers.com and Austin Auction Gallery.

Comments

Many freshwater mussels of the mollusk order Unionoida can produce freshwater pearls, also known as river pearls.

Freshwater and saltwater pearls form in the same manner. An irritant trapped in a mollusk stimulates the production of nacre and the formation of the pearl. Although both varieties share most of their chemical and physical properties, natural freshwater pearls have poorer luster and more irregular, baroque shapes. However, cultured freshwater pearls can now match saltwater pearls in appearance because of improved farming techniques.

freshwater pearl strand

Freshwater pearl strand. Photo by The Professional Jewelry Wholesaler. Licensed under CC By 2.0.

Of course, unusual shapes and textures can have their own appeal. Cultivators can also intentionally grow freshwater pearls into large and complex shapes, which offer unique options for the traditional June birthstone.

multi-armed cultured pearl

Multi-armed cultured freshwater pearl

Cultured Freshwater Pearls

Freshwater farming has some advantages over the saltwater process. Freshwater pearls can be seeded with just mantle tissue instead of a mother-of-pearl bead or other material. Cultivators place the foreign mantle tissue in the mantles of the host mollusk. Depending on the species, up to thirty of these fleshy “seeds” can be implanted.

opened freshwater mussel with cultured pearls

A newly opened freshwater mussel, Hyriopsis cumingii, showing rows of cultured pearls inside. Photo by Istara. Licensed under CC By 3.0.

After one to two years, the pearls can be removed, wrapped in new mantle tissue, and reinserted into the mollusk. This technique makes the pearls grow rounder. With care, the mollusks can survive the removal of pearls, and farmers can use them again to grow more product. The pearls grown in this manner are called beadless. All perliculture is a complicated process, but freshwater cultivation generally has a higher success rate than saltwater.

For more information on cultivation techniques, see our article on freshwater cultured pearls.

Biwa Pearls

Commercial freshwater pearl farming originated in Lake Biwa, Japan at the end of the 1920s. Cultivators can insert up to thirty seeds at a time into a single Biwa pearl mussel (Hyriopsis schlegeli). Production time for these pearls is just three years. Although people often use the term “Biwa pearls” to mean any cultivated freshwater pearls, the term strictly refers to those pearls from Lake Biwa.

Unfortunately, problems such as pollution and disease have severely hindered freshwater farming in Japan, despite efforts to restore ecosystems and the use of more resistant hybrid mollusks.

Lake Biwa pearls

“Cool Pearl…,” natural color Lake Biwa pearls with white and pink diamonds and ruby cabochons mounted in 18k rose gold. Photo by gemteck1. Licensed under CC By 2.0.

Chinese Cultured Freshwater Pearls

Today, China is the premier source of cultivated freshwater pearls due to advances in farming techniques. Additionally, marketing has made the Chinese freshwater pearl a much-sought gem. The triangle mussel (Hyriopsis cumingii) is the predominant source of Chinese pearls. It produces pearls with smooth shapes in sizes ranging from 4 mm to over 10 mm. The body colors are white to cream, orange, and purple.

The wrinkle shell or cockscomb pearl mussel (Cristaria plicata) lives in lakes and rivers in Asia. In China, Japan, South Korea, and Vietnam, cultivators use it to produce “rice krispie” pearls, so-called due to their irregular shapes and surfaces similar in appearance to the well-known breakfast cereal.

greenish freshwater pearl beads

Greenish “rice krispie” freshwater pearls. Photo by Mauro Cateb. Licensed under CC By 2.0.

American Cultured River Pearls

In the United States, the Tennessee River Freshwater Pearl Farm produces pearls from the washboard mussel (Megalonaias nervosa). This mollusk produces pearls in sizes and colors similar to those of the triangle mussel.

Tennessee river pearl ring

14k yellow gold ring with a baroque Tennessee river pearl, 22 x 8 mm, and two diamond accents. Photo courtesy of liveauctioneers.com and Watch Auction HQ.

Enhancements

Cultivated freshwater pearl colors range from white to tan and gray, depending on the mollusk species. Treatments are very common. Unless a seller specifically states otherwise, assume a pearl has been at least bleached. This process removes dark spots of conchiolin that show through the nacre. More dramatic techniques, such as dyes or radiation, produce pearls with exotic colors such as green, rose, and lavender.

freshwater pearl and garnet necklace

Sterling silver drop necklace with natural gray freshwater pearls and rhodolite garnet accents. Photo by Naomi King. Licensed under CC By 2.0.

Sources

Today, pearl-producing freshwater mollusks are rarely found in the wild due to pollution and other environmental disruptions. Once widespread in Europe, Asia, North America, and South America, these creatures are endangered almost everywhere they can still be found.

  • Europe: Austria; Finland; France; Germany; Ireland; Norway; Sweden; England, Scotland, Wales, United Kingdom.
  • North America: Nova Scotia, Canada; the Mississippi River and tributaries, United States.
  • South America: Amazon River basin.
  • Asia: China; Japan; South Korea; Southeast Asia.
pearl mussel - Scotland

A freshwater pearl mussel on the banks of the River Spey, Scotland, UK. Photo by Des Colhoun. Licensed under CC By-SA 2.0.

Stone Sizes

Sometimes, jewelers measure individual pearls in grains. One grain equals 0.25 carats. Please note: a grain as a unit of measurement has other values when used for other materials, such as gold.

Some well-known freshwater pearls include the following:

  • The largest known natural freshwater pearl is the 361.4 grains (90.35 carats) pink colored Survival Pearl. This baroque pearl formed in the shape of a snail that evidently entered a freshwater mollusk in Tennessee. The mollusk survived for 50 to 70 years after that intrusion, creating the unusual shape.
  • Discovered near Paterson, New Jersey in 1857, the Queen Pearl is round, pink, and translucent. It weighs 93 grains (23.25 carats).
  • The Abernathy Pearl, 44 grains (11 carats), was discovered in 1967 in the River Tay in Scotland.

Care

All pearls require special attention. See the main pearl listing as well as our detailed pearl care guide and pearl engagement ring guide.

amber and freshwater pearl necklace

Amber and freshwater pearl necklace. Photo by Irenka Kudlicki. Licensed under CC By 2.0.