Pearl types

Although almost most people know that oysters make pearls, a common misconception is that the next plate of oysters might contain a gem. Edible oysters do in fact sometimes create pearls made of calcium carbonate, similar chemically to commercially cultured pearls, but these pearls may crack your tooth. However, these pearls do not contain nacre so they resemble small white marbles. Oysters and freshwater mussels, the animals that create pearls, are all from the phylum Mollusca or mollusks. A mollusk is defined by a specialized tissue called the mantle, which is the thin tissue membrane that attaches a mollusk to its inner shell. Mollusks live in saltwater, freshwater, and even land. They include snails, slugs, clams, mussels, scallops, oysters, octupus, squid, chitons, and more. On the other hand, most pearl-producing mollusks are edible but not tasty.

When a foreign particle (usually microscopic parasites), lodges itself between the mollusk shell and mantle, a natural pearl is created. If the particle is small or flat, the particle becomes a blister pearl or part of the shell. The shell simply secretes more nacre to cover the particle that is attached to the shell. If a larger particle enters the mollusk or the mantle tissue curves around the particle, this pocket becomes a pearl sack that secretes nacre to cover the particle ?which is now the nucleus. Since natural pearls are rare, pearl farmers create a pearl by inserting a piece of mantle tissue and, in saltwater mollusks, a round bead made from a freshwater mollusk shell. For a freshwater mollusk, the pieces of mantle tissue are used as nuclei alone.

All real pearls should first be classified as natural or cultural pearls. Nearly all pearls in jewelry or department stores are cultured pearls. is one of the few that carries natural pearls in our vintage line. These pearls are relatively small or approximately 2mm. Roughly one in 10,000 uncultivated oysters will yield a pearl, but 90% of these pearls are below 1.75 mm and only 0.5% of these natural pearls are larger than 6 mm. Natural pearls are so rare that they are typically sold at auctions like Sotheby's or Christie's for thousands of dollars if they are larger than 6 mm. Natural pearls are difficult to find on the market, and the cultured pearls of today rival the finest natural pearls of the past. After a pearl has been classified as natural or cultured, it may also be classified from either in saltwater or freshwater. Saltwater pearls are grown in oysters that inhabit ocean and seas. Freshwater pearls are grown in mussels that inhabit lakes, rivers, and non-salt environments.

Imitation pearls are man made by mechanical processes and do not have any real value. Better imitation pearls are made from beads of glass or shell, coated with a varnish generally made of lacquer and ground fish scales to simulate the iridescence and color of a pearl. Imitation pearls may be called "fashion, faux, simulated, organic, man-made, or Majorica^®" pearls. Pearl experts may be able to distinguish between imitation and real pearls by sight alone. However, it may be difficult for the average consumer to distinguish between a natural or cultured pearl from a good imitation by sight. An easy way to tell the difference is the "tooth" test. An imitation pearl slowly rubbed across the front teeth will feel smooth whereas a natural or cultured pearl will feel a little gritty. The texture of a real pearl is from the crystalline structure of nacre.
There are many mollusks that grow pearls, however, the most popular commercial pearls of today are Akoya, Freshwater, South Sea and Tahitian.

Freshwater

Approximately 350 species of freshwater pearl mussels can produce pearls. However, the most common freshwater mussel is Hyriopsis cumingii: Freshwater mollusks are grown in the waters of Japan or China. These pearls generally range in size from 2 mm to 18 mm and range in color from white, cream, gold, silver, pink, rose, lavender, plum, tangerine, and mocha shades.

Saltwater

Although 70 species of oysters can produce pearls, most of them belong to the Pinctada family. Below are the three most common oyster types.

• Pinctada fucata or Pinctada martensi: Akoya cultured pearls-producing saltwater mollusks grown in the cooler waters of Japan or China. Akoya pearls generally range in size from 2 mm to 10 mm and range in color from white, rose, or cream shades.
• Pinctada maxima: The world's largest pearl oysters found in the waters around Australia, Indonesia, the Philippines and Japan. Colors include silver-white, pink, cream, and gold. These oysters, also called Silver or Golden-lipped pearl oysters, grow in excess of 12 inches in length and can produce a wide range of South Sea cultured pearls in sizes from 8 mm to over 22 mm;
• Pinctada margaritifera: Saltwater mollusks grown in French Polynesia that produce Tahitian or “black?cultured pearls. Considered as adult at 3 years old, it has a diameter of 10 to 18 cm large. Some of these Black-lipped oysters can weigh up to 5 kg (11 lbs.), live 30 years and reach 30 cm (12 inches) in diameter.

Name	Species	Type	Size	Colors	Origin
Akoya	Pinctada fucata	Saltwater	2 - 10mm	White body color with overtones of cream, gold, silver, green, blue, and rose	Japan & China
South Sea	Pinctada maxima	Saltwater	8 - 22mm	Silver-white, pink, cream, and gold	Australia, Myanmar, Indonesia, Thailand, Malaysia, Philippines, and more.
Freshwater	Hyriopsis cumingii	Freshwater	2 - 18mm	White, cream, gold, silver, pink, rose, lavender, plum, tangerine, and mocha	China, Japan, America, Thailand, Vietnam, India, and more.
Tahitian	Pinctada margaritifera	Saltwater	10 - 18mm	Grey, black, green & purple	French Polynesia