Saltwater Pearl Gems: Types, Properties, Meanings & Prices

One of the categories of pearls, saltwater pearls form in marine mollusks. Common examples are Akoya, South Sea, and Tahitian pearls.

Are saltwater pearls rare? Natural saltwater pearls are quite rare, so most saltwater pearl gemstones are cultured.

Today, we’ll go over all the differences between freshwater and saltwater pearls and what makes saltwater pearls so special, along with these gems’ prices, history, and more!

Pictured above: Tahitian black saltwater pearl ring

What Is A Saltwater Pearl?

Saltwater pearls are semi-precious gemstones, though some consider pearls precious gems. Common types of saltwater pearls include:

• South Sea Pearl

• Tahitian Pearl

• Akoya Pearl

• Cortez Pearl

• Abalone Pearl

We’ll get into each of these a little later.

Pearls are the classic June birthstones, along with being the 30th wedding anniversary gem. Astrologically, pearls are lucky Gemini and Cancer stones.

Saltwater Pearl Specifications & Characteristics

Technically, saltwater pearls aren’t minerals. They contain calcium carbonate in the form of calcite, aragonite, or both, but they’re mineraloids. They’re also organic gemstones.

Overall, a pearl is an irritant surrounded by “nacre,” layers of calcium carbonate held together by an organic protein called conchiolin. Thicker nacre means brighter luster.

Saltwater pearl properties listed:

• Mohs hardness: 2.5-4.5

• Color: Body color and overtones vary (see “Types of Saltwater Pearls” section)

• Crystal structure: Partly orthorhombic (calcium carbonate layers)

• Luster: Dull, pearly, or metallic

• Transparency: Translucent to opaque

• Refractive index: 1.53-1.69

• Density: 2.61-2.78; Varies by species and source

• Cleavage: None

• Fracture: Uneven/irregular

• Streak: White

• Luminescence: Fluorescence present in SW-UV & LW-UV - colors vary by type

• Pleochroism: None

• Birefringence: 0.155

• Dispersion: None

• Optical effects: Orient iridescence

Pictured above: Freshwater cultured pearl bracelet

Saltwater vs Freshwater Pearls

The main categories of pearls are natural vs cultured (or “cultivated”) and saltwater vs freshwater.

Cultured pearls form like natural pearls, but humans insert the irritant that kicks off pearl formation in the mollusk.

Saltwater pearls form in mollusks from marine (saltwater) environments like oceans and seas, while freshwater pearls form in mollusks that live in freshwater.

Both can be natural or cultured, but natural freshwater pearls are easier to find.

Freshwater mollusks can produce more than one pearl at once. Saltwater pearls are only formed one or two at a time and take longer.

That said, freshwater pearls are usually smaller, less colorful, more irregularly shaped, and less lustrous than saltwater pearls.

Types of Saltwater Pearls

Almost all saltwater pearls today are cultured, as natural ones are rarer and cultured ones are generally higher quality.

Akoya Pearl

Arguably the most well-known, Akoya pearls have a strong, even luster and internal glow because their nacre is so thick.

Cultured Akoya pearls often have great roundness, reflection, and white colors with overtones of silver, rose, or cream. They can also be dyed into virtually any color, like the popular midnight blue.

• Colors: White, blue, gold, yellow, silver-blue; Overtones in pink, green, or silver

• Mollusks: Akoya oysters Pinctada fucata martensii and Pinctada fucata chemnitzii

• Size: 2-11 mm; Very rarely over 10 mm

South Sea Pearl

The name “South Sea” derives from the original cultured pearls being farmed in seas south of Japan, though these pearls come from other areas, too.

White to gold South Sea pearls are often considered the most valuable pearls. Plus, the rarest, biggest cultured pearls are South Sea pearls.

The natural color of South Sea pearls depends on the oyster’s color, with their iridescent overtones matching the oyster shell’s nacre. Their luster is lower than Akoya, however.

• Colors: White, gold, silver, pink, cream, or a combination; Possible iridescent rainbow overtones

• Mollusks: Pinctada maxima oysters

• Size: Usually 8-20 mm

Tahitian Pearl

Tahitian pearls are popular, large pearls with dark colors and cool overtones. They aren’t as rare as they used to be, but they’re more valuable than Akoyas.

They’re nicknamed “black pearls,” since they form in black-lipped oysters, but black isn’t exclusive to Tahitian pearls.

These pearls are also famous for their overtones, such as the green-rose-gold “peacock.”

• Colors: Black, gray, brown, green, blue, purple, or “peacock”; Overtones in purple, green, pink, blue, silver, rose, gold, green, or combination

• Mollusks: Pinctada margaritifera oysters

• Size: 8-17 mm

Cortez Pearl

Image credit: What's Up San Carlos

Cortez pearls (also called Concha Nácar) are rare varieties from the Sea of Cortez in Mexico. They’re known for their thick, lustrous nacre and colorful iridescence.

Additionally, Cortez pearls will fluoresce red under UV light.

• Colors: Silver, gray, black, bronze, gold, blue, turquoise, emerald, olive, purple, pink; Overtones of blue, green, violet, pink, or combination

• Mollusks: Rainbow-lipped Pteria sterna & black-lipped Pinctada mazatlanica oysters

• Size: 8 -14 mm; Rarely over 10 mm

Abalone Pearl

Abalone pearls are unique in many ways. First, they form in gastropods (sea snails) called abalones or “ear shells.” Second, their shape is usually horn-like, though they can be rounded or freeform.

High-quality abalone pearls are extremely rare. Most are blemished and sometimes hollow. They’re known for having dark colors and vibrant iridescence.

• Colors: Usually green, blue, or yellow; Can be white, cream, gray, black, blue, purple, pink, or gold; Bright red iridescence

• Mollusks: 96 known varieties, from genus Haliotis

• Size: Widely variable

Pictured above: "Cultivation of pearl oysters in Japan. The work on the oyster farm is done almost entirely by women. Here are women divers, with no other equipment than their baskets, bringing up pearl-oysters from the deep-sea beds." From Frank Coffee's 1920 book Forty Years On the Pacific | Image credit: Courtesy of Popular Science, Public domain

Saltwater Pearls History

It’s no secret that pearls have a long history of folklore and ancient uses, both decorative and healing. You can read more about these in our Pearl Gemstone Info Guide.

Here, we’ll focus on the history of cultured saltwater pearls.

Pearl cultivation dates back to 13th century China, when farmers used freshwater mussels to create blister pearls using unique molds like Buddha shapes to create flat pearls.

Centuries later in 1902, three Japanese men — Dr. Tokichi Nishikawa, Tatsuhei Mise, and Kokichi Mikimoto — all independently created processes for seeding oysters to create round pearls.

By 1921, the first round cultured saltwater pearls for sale hit the gemstone market.

This introduction made pearls more accessible, as they could be made more quickly and safely.

South Sea pearl cultivation started in the 1950s and Tahitian pearl cultivation began in the 1960s. Black cultured Tahitian pearls came in the 1970s.

Pictured above: Bluish-silver Japanese Baroque Akoya pearl necklace

Saltwater Pearl Gemstone Properties

Are saltwater pearls worth anything? Absolutely! Saltwater pearls are more valuable than freshwater pearls and often more expensive because they’re higher quality and rarer. But their value depends on their quality.

Pearls have unique value grading criteria, and different types have different grading systems. Overall, the seven grading factors are: luster, shape, color, surface blemishing, size, formation, and matching.

Luster

Better pearl luster means brighter, more clear or even mirror-like surface reflections. Akoya pearls tend to have the best luster.

Shape

Pearls can have 8 different shapes, but the primary types for grading are spherical, symmetrical, and asymmetrical (e.g. baroque).

Irregular shapes are more common, so rounder means more valuable.

Color

Similar to precious opals, saltwater pearl colors have different elements: body color, overtone, and iridescence (called “orient”). Exhibiting all three can boost value.

Naturally blue pearls are rarest. The most valuable color is a “22K to 24K gold” South Sea pearl.

Surface Blemishing

Various surface blemishes can lower saltwater pearls’ durability and value. Blemishes are common, but fewer visible ones are best. The GIA grades these from Heavily Spotted to Clean.

Additionally, durability can rely on the nacre. Thicker coatings are best.

If it’s drilled, you can often tell if a saltwater pearl is real by looking for a bead nucleus in the drilled hole.

Pictured above: Tahitian pearl size diagram | Image credit: Hoanggiapearl, CC-BY-SA-3.0

Size

Round pearl size is given as diameter (in millimeters), while other shapes are measured in more dimensions.

Most times, larger pearls of high-quality will command much steeper prices.

Formation (Natural vs Cultured)

Given their rarity, good-quality natural saltwater pearls will almost always be more valuable than cultured pearls.

Matching

Finding two pearls with uniform appearance and shape is rare, so closely matched pearls carry higher value. It can take years to find enough to make a matching saltwater pearl necklace.

Treatments

Pearl treatments will lower a pearl’s value but also open up possibilities for new colors and improved shape or luster. Common saltwater pearl treatments are bleaching, dyeing, surface coating, and irradiation.

A common one is dyeing to create artificially black — technically midnight blue or blue-black — saltwater pearls.

Pictured above: Pinctada margaritifera - Two views of same specimen | Image credit: Didier Descouens, CC-BY-SA-4.0

Saltwater Pearl Formation & Sources

Saltwater pearls usually grow in oysters within the Pteriidae family. An irritant enters, so the oyster covers the irritant in layers of nacre to protect itself.

In cultured pearls, pearls are made after the irritant or “seed” is inserted.

Mining Locations

Most saltwater pearls are found in mollusks from the South Pacific and Indian oceans.

The top sources of each saltwater pearl variety are:

• Akoya Pearls: Japan, China

• South Sea: Australia, Philippines, Indonesia

• Tahitian Pearls: French Polynesian islands

• Cortez Pearls: Mexico

• Abalone Pearls: California, Australia, Japan, Korea, China

How much is a saltwater pearl worth?

Saltwater Pearl Price & Value

Overall, natural saltwater pearls can range from $500 to over $8,000 each.

Here are the prices to expect for round cultured saltwater pearls:

White Akoya, 6-9.5 mm:

• Single: $90 to $4,500

• Matching Pair: $250 to $10,000

White South Sea, 8-14 mm:

• Single: $450 to $8,100

• Matching Pair: $1,000 to $18,000

Golden South Sea, 8-14 mm:

• Single: $315 to $5,400

• Matching Pair: $700 to $12,000

Black Tahitian, 8 to 13 mm:

• Single: $180 to $1,500

• Matching Pair: $400 to $3,350

Last up is gemstone care, crucial for all pearls.

Saltwater Pearl Care and Maintenance

Saltwater pearls require special care. They’re sensitive to acids, ammonia, and scratches. Keep your pearls away from:

• Cosmetics, perfumes, and hair products

• Household cleaners

• Perspiration (wear on top of clothes)

• Mechanical cleaning systems

You can clean saltwater pearls by wiping it with a thin cloth dipped in a mixture of warm water and mild soap. Use a soft brush to get grime out. Dry it with a microfiber cloth and lay on an absorbent material like a Turkish towel. Don’t use heat for drying.

Use protective settings for saltwater pearl jewelry. Store away from other jewelry in a temperature-neutral place (away from intense heat or cold).

Pictured above: Golden South Sea pearl in 9K yellow gold necklace

Saltwater Pearls: A Timeless, Classic Gem!

Pearls are among the most classic gems, and saltwater pearls bring a modern variety of colors and iridescence to this timeless option!

Buy saltwater pearl gemstones today!