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Pearl Cultivation and Popular Pearl Varieties

Anna is an artist, collector, and pearl enthusiast who enjoys researching and identifying pearls.

Did you know that most of the pearls used in jewelry are cultivated specifically for that purpose?

Did you know that most of the pearls used in jewelry are cultivated specifically for that purpose?

What Is a Pearl?

The pearl is one of a few gems that come from living creatures. It is also the only gem that, when harvested, often doesn't require any cutting or reshaping to be used in jewelry. Most pearls do, however, still go through a polishing process to give them additional shine and enhance their luster.

Pearls come in a variety of shapes and sizes, but most of the pearls available in the world are cultivated rather than found. It is actually very rare to find natural pearls in the wild. Natural pearls occur when an irritant enters the mantle of a mollusk. The response of the creature is to form a "nacre," or inorganic composite material, around the irritant to protect itself; this ends up becoming a pearl.

Cultured pearls are the same, but the irritant, usually a piece of mother-of-pearl or flesh from a donor mollusk, is placed inside the mantle on purpose. The mollusk then starts the process of building a pearl around the irritant. The number of pearls found find inside one shell depends on how many pieces of irritant are introduced. Cultivators can put multiple irritants into a single mollusk shell so that it produces more pearls. The cultivation process ensures that each mollusk or oyster is guaranteed to develop one or more pearls inside.

Where Are Pearls Cultivated?

Most commercially available pearls come from China. Pearl farming in China is mainly concentrated in the southeastern part of the country in the Zhejiang province. This area is the source of most of China's freshwater pearls.

What Are Cultivated Pearls Used For?

Pearls are produced by the ton for several commercial uses. While they are most commonly used for jewelry, some are crushed into a powder and used for cosmetics, paint, or medicines.

How Are Pearls Graded and Valued?

Pearls are graded between A and AAAA, with AAAA being the highest quality. The most valuable pearls are round, have excellent luster, and have a smooth surface.

4 Popular Pearl Varieties

Four of the most popular cultivated pearl varieties are akoya, freshwater, Tahitian, and South Sea. In this section, we'll discuss each type in terms of shape, size, luster, color, and other characteristics.

Akoya pearls are higher in quality than freshwater pearls but often slightly lower in quality than Tahitian or South Sea pearls.

Akoya pearls are higher in quality than freshwater pearls but often slightly lower in quality than Tahitian or South Sea pearls.

1. Akoya Pearls

Akoya pearls are saltwater pearls produced in China and Japan. Akoyas are the most popular kind of saltwater pearl, as their luster and shape are far superior to those of freshwater pearls. They are quite sought after for jewelry applications and are more expensive than freshwater varieties. Akoya pearls are generally ranked third in terms of quality after the Tahitian and South Sea varieties.

  • Size: Between 2 and 11 mm (most commonly 6–8 mm)
  • Shapes: Round, nearly round, baroque
  • Colors: White, cream
  • Hues: Yellow, pink, blue
  • Overtones: Pink, green
  • Luster: Good to excellent
  • Surface: Smooth to lightly spotted
Freshwater pearls are cheaper and more widely available than their saltwater counterparts.

Freshwater pearls are cheaper and more widely available than their saltwater counterparts.

2. Freshwater Pearls

Freshwater pearls are cultivated in large quantities in ponds and freshwater lakes and are the most popular type of pearl with consumers. Freshwater pearls come in a wide range of sizes, shapes, and colors, and they tend to be lower in price than their saltwater counterparts.

Pearls with colors such as hot pink, pineapple yellow, denim blue, bottle green, and so on are all dyed. Modified pearl shapes occur when the mother of pearl inserted into the mantle is already that shape, so the nacre just follows the general form of the irritant. To achieve a more naturally occurring shape, round or oval irritants are used.

Edison pearls, which range from 9 to 14 mm in size, are also freshwater pearls; they are sort of like the freshwater counterparts of Tahitian pearls, but they are not as valuable or expensive. When ordering from a supplier, you can choose oysters with pearls that may have singles, twins, triplets, quads, quints, and even 10s and 20s.

  • Size: 4 to 14mm
  • Traditional/Naturally Occurring Shapes: Round, nearly round, rice/oval, baroque
  • Modified Shapes: Star, cross, moon, square, button
  • Colors: White, pink, light yellow, purple, cream
  • Hues: Yellow, orange, blue
  • Overtones: Pink, green, blue
  • Luster: Good to excellent
  • Surface: Smooth to lightly spotted
Tahitian pearls are often black, brown, or gray.

Tahitian pearls are often black, brown, or gray.

3. Tahitian Pearls

Tahitian pearls are cultivated around the islands of French Polynesia near Tahiti. These saltwater cultured pearls are sometimes called black pearls because they come from black-lipped pearl oysters (Pinctada margaritifera) and may appear black, gray, or brown due to the black lips of the oysters' shells.

These pearls are costly and highly sought after. They are made into solitaire pendants, strings, necklaces, rings, and so much more. Some luxury jewelry stores carry only this type of pearl because of its quality and rarity.

  • Size: 9 to 14 mm
  • Shapes: Round, nearly round, oval, drop, button, circled, baroque, semi-baroque
  • Colors: Black, neutral, gray, brown
  • Hues: Blue-green, purple, yellow-green
  • Overtones: Pink, green, blue
  • Luster: Good to excellent
  • Surface: Smooth to spotted
South Sea pearls are known for their color and high quality.

South Sea pearls are known for their color and high quality.

4. South Sea Pearls

South Sea pearls are beautiful and dramatic. Their colors range from white to silver to deep, rich gold. Like Tahitians, these pearls get their color from the lips of the oyster shells in which they form. The golden pearl's oysters are called Pinctada Maxima.

These precious and costly pearls come from Australia, Indonesia, and the Philippines. They are massive and have a thick nacre due to their long growth periods. They are closely monitored and scrutinized and are grown in smaller quantities and better conditions than most pearls. A French company called Jewelmer owns most of the pearl farms in the Philippines.

  • Size: 8 to 20 mm (13 mm average)
  • Shapes: Round, nearly round, oval, drop, button, circled, baroque, semi-baroque
  • Colors: Neutral, white, cream, silver
  • Hues: Yellow, orange-yellow, blue
  • Overtones: Pink, green, blue
  • Luster: Good to excellent
  • Surface: Smooth to lightly spotted

What Are Monster Oysters?

Monster oysters, which are trendy in pearl-party openings, are very large mollusks that have anywhere from 20 to 30 pearls inside. This means that 20 to 30 irritants are introduced into the oyster's mantle, thus producing numerous pearls.

A sack covers each pearl. The pearls are white, cream, pink, and purple in color. They are primarily grown in China, and most commercial freshwater pearls come from these oysters. The polished shells are also sold as souvenirs, so no part of this mollusk is ever wasted. Humans do not consume the flesh of this particular mollusk. Instead, they are sold to a third party and made into animal feed or fertilizer.

What Happens to the Oyster Shells?

The shells are comprised of a material known as mother of pearl. Not a single part of the mollusk is discarded. Some shells are polished and sold as souvenirs, while others are used as caviar plates, jewelry caddies, and decorations.

Some shells have blisters, which are actually pearls that have attached themselves to the shell and become covered in nacre. It is not advisable to remove these pearls from their host shells, as doing so could damage them.

Shells with blisters can also be turned into jewelry. Pieces of the shell are cut with the blister in the middle to preserve the shape of the pearl. These are then polished and sol—mostly as pendants. These pearls are also called Mabe pearls. Some mabe pearls are deliberately embedded with a round or heart-shaped bead so they can achieve a unique shape and larger size.

Mother of pearl is ideal for serving caviar because it does not alter the caviar's delicate flavor. Mother of pearl is also used to produce caviar spoons, forks, and knives.

What Is a Pearl Party?

Pearl parties involve a company or individual using a social media outlet to shuck oysters live so viewers can see the "unboxing" of the pearls. Viewers have typically ordered the oysters/pearls online before the party.

Rules Surrounding Pearl Parties

  • Oysters that are used in pearl parties are considered imports, meaning sellers are required to have an import/export license before their first shipment.
  • The import/export license costs $100 and is valid one year from the date of issue.
  • This kind of activity is Regulated by the U.S. Fish and Wildlife Service because oysters are considered wildlife even if they are farmed.
  • Each shipment of oysters is required to enter the U.S. in a designated port.
  • Each shipment has to be declared and fees need to be paid.

For further information, contact The U.S. Fish and Wildlife Service

How Do Pearl Farms Work?

Pearl farms vary in size depending on their location and the variety of pearls they are cultivating. Pearls are cultivated in a few ways, one of which involved depositing oysters on trays hung from ropes in the sea. Depending on the kind of pearl, they can be placed at a depth of between 30 and 108 or more feet. Growers determine how deep to situate their oysters to create ideal conditions that promote the growth and health of the mollusks.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.