Cultured Pearl Types and Varieties

Freshwater, Akoya, South Sea and Black Tahitian Pearls

Apr 6, 2009

Cultured pearls come in all shapes, colors and sizes and are vastly popular in bridal jewelry and necklaces. Read on for the most popular varieties of farmed pearls.

Pearls have long been valued as a remarkable natural gem that grows inside a living oyster, clam or other mollusk. Naturally occurring pearls are rare, but cultured pearls can be produced reliably without compromising the luster, color or shape of a quality pearl. There are several popular varieties of cultured pearls, including freshwater, Akoya, Tahitian, and south sea pearls.

How Pearls Are Made

Pearls form naturally when a clam, oyster, or other shelled mollusk traps a particle of dirt or any foreign matter inside. The mollusk rolls this material around and around inside its shell, coating it in a fine glaze of the hard, glittering substance called nacre. As an object is coated in layer after layer of nacre, it becomes a hard, round gem called a pearl.

How Cultured and Natural Pearls Differ

Natural pearls occur fairly seldom. Searching for wild pearls is a matter of chance and persistence, since relatively few shells will be found to contain pearls, and not every pearl is of good enough quality to be made into jewelry.

Cultured or farmed pearls are made by introducing a bead or other small, round item into a mollusk. The bead is coated with a bit of tissue from another mollusk to start a reaction that will eventually create a pearl. This process, known as nucleation, provides a more reliable source of pearls of any size or color.

There are several types of cultured pearls. Read on for details on some of the most common pearls used in jewelry.

Cultured Freshwater Pearls

Freshwater pearls are produced by freshwater mussels. These pearls are mostly in China, although some are also grown in Japan and the US.

Freshwater pearls can be found in almost any natural pearl color except black. They are seldom round, but can be found in many other shapes, including button, rice, drop and baroque. They grow for 2 to 7 years and may be 1mm to 16mm in diameter.

Akoya Pearls

These pearls are the most popular type sold today. Akoya are saltwater pearls, grown mostly in Japan and China. They are perfectly round, making them ideal for necklaces, pearl strands, and other jewelry requiring uniform size and shape.

Akoya pearls occur in a very limited range of colors; they are white with a subtle silvery, rose, or ivory overtone. The Akoya oyster is small in size, so the pearls are limited to a maximum size of 10mm and the average size is about 7mm.

Tahitian Pearls (also Black Tahitian Pearls)

Black Tahitian pearls are much desired, with reason: the Tahitian pearl is the only variety that grows natural black pearls (other black pearl varieties are dyed). Tahitian pearls are grown in black-lipped oysters and show a range of overtones (gray, silver, green, blue, purple) on black pearls as well as lighter colored pearls.

Black Tahitian pearls are large, between 9 and 16mm, and they are predominantly farmed in French Polynesia and sold in Tahiti. They come in a wide variety of shapes.

South Sea Pearls

South sea are the largest and most expensive cultured pearls, growing up to 20mm and averaging about 13mm. The pearls grow for six years in the warm waters of Australia and Indonesia.

Cultured south sea pearls have a thick nacre, glowing luster and come in a variety of colors from white to gold. They come in many shapes, but only 15% of south sea pearls are perfectly round.

Reference

The copyright of the article Cultured Pearl Types and Varieties in Gemstones is owned by Victoria Anisman-Reiner. Permission to republish Cultured Pearl Types and Varieties in print or online must be granted by the author in writing.