Freshwater vs Saltwater Pearls: How Do They Differ?

Last Updated on April 18, 2023 by Juli "Jewels" Church

Wondering if you should buy freshwater pearls or saltwater pearls?

Perfect! You're in the right place.

The world of pearls is more complex than most think. In this Learning Guide, I'll answer some of the most common questions asked about pearls and their origins like

freshwater vs saltwater pearls
  • How Does A Pearl Form?
  • Are Saltwater Pearls More Expensive?
  • What's the Difference Between Cultured and Natural Pearls?

How is a Pearl Formed?

You may or may not have heard the story that pearls are formed when an irritant like a grain of sand enters a clam, it covers the sand with a shiny substance called nacre.

It coats the irritant over and over again forming layers to create a pearl. This is the traditional story of how pearls are formed. But it's not exactly accurate. 

Pearls don't come from clams like you see in the cartoons. They actually come from mollusks, like mussels and oysters. There are many different kinds of mollusks. The irritant that's introduced isn't usually sand either. Most often, it comes from a parasite.

The Gemological Institute of America also has a record of a piece of coral being the an original irritant in a study.

The mollusk does coat the irritant in nacre, but most people don't know what nacre is. Nacre is made up of thin layers of the mineral aragonite . Aragonite is a common calcium carbonate mineral similar to calcite. 

Mother of pearl is usually at the center of pearl. Hexagonal aragonite plates (shown below) are layered over the mother of pearl bead to give its luster and beauty. The layers of nacre create the ending pearl. That's the way natural pearls are formed.

aragonite plates - Creative Commons

Natural round pearls are very rare.

In the jewelry market today, you probably won't find too many natural pearls for sale, let alone a whole strand of perfectly round ones. Natural pearl strands can go for hundreds of thousands. 

Cultured pearls are the name we use when we basically "lab create pearls". In lab created diamonds, scientists emulate the conditions it takes for a diamond to form in the ground and grow it in a lab. 

Similarly, cultured pearls happen when a pearl farmer introduces the irritant to the mollusk instead of it happening on its own by chance. These or imitation pearls make up most of the pearl jewelry market. 

Freshwater vs Saltwater Pearls: Origin

Freshwater and saltwater pearls form in the same way, as mentioned above. 

Freshwater Pearls

Freshwater mussels can be found in ponds, lakes, reservoirs, and most commonly, rivers.

A freshwater pearl can come from many different types of mollusks, but this rarely occurs naturally. Cultured freshwater pearls are the most common types of pearls in the world. A single freshwater mussel can produce up to 50 pearls at a time, but the farm limits to around low 30s. 

Lots of freshwater pearls are cultivated in China. They have been in pearl culturing business dating back to the 13th century. However, it wasn't until after Mikimoto's discovery of Akoya saltwater pearls that led to attempts to culture freshwater pearls. 

Dr. Fujita Masao started with the Biwa pearly mussel. Taking a keshi pearl (pearls without a nucleus, also called non-nucleated) from an Akoya pearl mollusk, and introduced a bit of the mantle to the Biwa mussel. It resulted in small 3.5mm baroque (non-round) pearls. 

Chinese Professor Xiong Daren took Fujita's research and tried it with triangle sail pearl mussels and found even more success. The Chinese later changed their pearl mussels to cockscomb mussels. 

Depending on the desired size of the freshwater pearl, it can take between 6 months to 7 years for a mollusk's pearls to be ready. 

Saltwater Pearls

Saltwater pearls can be found in areas from Australia to Asia. Most saltwater pearls come from oysters. There are three main types of saltwater pearls: Tahitian, Akoya, and South Sea pearls.  Natural saltwater pearls are very rare and fetch extremely high prices on the market. 

Cultured Tahitian pearls are grown in French Polynesia and cultured in Tahiti. They come from the pinctada margaritifera cumingi oyster. 

Mixed color Tahitian pearl bracelet from Blue Nile

Cultured South Sea pearls come from the saltwater oyster pinctada maxima. South Sea pearls can be grown in Indonesia, the Philippines, Australia, and Myanmar (Old Burma). 

Gold & white South Sea Pearl necklace from Blue Nile

Cultured Akoya pearls come from Japan mainly, but are also found in China, Thailand, Vietnam, and Australia. 

cultured akoya pearls

Freshwater vs Saltwater Pearls: Appearance

Freshwater Pearls

Even though freshwater and saltwater pearls mostly have the same optical and chemical properties, you'll be more likely to find irregular shapes, or baroque shaped pearls.

Nowadays, they've improved pearl farming techniques. 

In early pearl farming, freshwater pearls usually had less luster than their marine counterparts because the nacre is thicker. Thankfully, new pearl farming techniques have improved it tremendously to where the average person won't notice a difference. 

Freshwater pearl jewelry comes in a variety of shapes, but the most common are teardrop, ovals, and round pearls. They also come in a few different colors, like white, pink and gold. Some freshwater pearls can be irradiated to look black or metallic colored. 

Since a freshwater oyster can produce so many pearls at once, they don't usually get as big as saltwater pearls.

Saltwater Pearls

Of the three main saltwater pearl varieties, Akoya pearls are probably the most popular. Akoya pearls are mostly white or ivory colored. They can also have a pinkish overtone. They have very good to best luster and iridescence. 

Most Akoya pearls are round shapes, making them perfect for the classic pearl necklace. They range in size from as small as 2mm to around 9mm. Above this is uncommon and rare.

Akoya and Diamond studs from Blue Nile

Tahitian pearls are the saltwater grey to black pearl variety. These beautiful pearls may have overtones of green, pink, and blue. Purple overtones can happen, but it's very rare. You can find them in either round or baroque shapes. 

Tahitian pearls are usually medium to large size, commonly found between 8-10mm. Tahitian pearls bigger than this can be found, but over 16mm is rare. 

South Sea pearls come in white and yellow to gold varieties. They may have light overtones, but not too noticeable like other varieties. Personally, I love golden south sea pearls. 

South sea pearls are larger than the other pearl varieties, commonly being found between 10-14mm. Over 16mm is rare. They produce round and baroque pearl shapes.

Tahitian pearls are usually medium to large size, commonly found between 8-10mm. Tahitian pearls bigger than this can be found, but over 16mm is rare. 

Freshwater vs Saltwater Pearls: Price

The price of pearl jewelry depends on a number of factors. 

The most common ones will be the type, size, origin, and luster. If the piece of pearl jewelry has more than one pearl, how well they match is a significant price factor as well. 

A matching pair of white freshwater pearls with high luster and a 6-7mm size can go for 60-$140. For top luster, you're looking at $100-140. The biggest white freshwater pearl earring set can go for around $250-380 for high luster and $300-500 for the pair. 

Because South Sea pearls are the largest variety of pearls, they fetch the higher prices. A pair of white South sea pearl earrings may run around $5300 to $18,000. A pair of golden South Sea pearls of the same size are priced around $4,000-$12,000. 

A matching pair of white Akoya pearls at their largest size (9-9.5mm) may cost 1200-10,000 with top luster and $800-$5,000 for high luster.

Freshwater vs Saltwater Pearls: Value

Since freshwater pearls are produced in higher quantities at a time and are smaller than saltwater pearls, they have lower value because they aren't as rare. Additionally, freshwater pearl jewelry also shows wear quicker than saltwater pearls, so they don't last as long either, decreasing the value further. 

Now, when we say "decrease in value", we're mainly talking about overall prices, which were already mentioned above.

For investment purposes, freshwater pearl jewelry isn't going to be where your money should go into.

Another detail that contributes to the value of a pearl is the treatment it's been given. Treatments are given to pearls pretty regularly to enhance color, but certain treatment decrease value more. 

You should always ask the jeweler about any treatments that have been done to the pearls before buying them. Some treatments are permanent and others may be temporary.

Pearls can receive many different types of treatments. 

Dyed pearls impact their value. Pearls retain dyes well, so many times they are colored unique colors like red and orange with dye. Dyes decrease value dramatically. Silver nitrate will dye pearls black. Dyes will fade over time and their value is decreased because it's easier to find matching dyed pearls. 

Irradiation treatments cause a pearl to darken to a blue or gray color. This is also permanent. For saltwater pearls, the seed darkens and for freshwater pearls, the nacre darkens. It makes them more iridescent and metallic looking, but it does decrease value and price. 

Lastly, the highest valued pearls are natural pearls of course. If you could find a large South Sea natural pearl, it may cost 10-20x the price of a cultured South Sea pearl. Natural pearls are extremely rare because most have been harvested already. It should be assumed that most in-store pearl jewelry will be cultured pearls. 

Bottom Line: Freshwater vs Saltwater Pearls

In the battle of freshwater pearls vs saltwater pearls, I can say that saltwater pearls are going to be a better use of your money once you find the best place to buy pearls.

Here's why:

  • They have better luster than freshwater pearls
  • They are more durable than freshwater pearls
  • Many colored freshwater pearls are often dyed
  • Freshwater pearls don't get very big
  • Saltwater pearls are a better investment
  • Saltwater pearls are considered high quality

Of course, some of these reasons may not apply to a pearl buyer. Perhaps you just want an inexpensive piece of pearl jewelry or a certain color for a cheaper price. Freshwater pearls are excellent options for an affordable yet timeless look. 

For that reason, you should always choose the one that works best for you and your wallet! 

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