Pearl Types

Pearls can be divided into three categories based on its formation: natural, cultured and imitation. Before the depletion of natural pearls, about a century ago, all pearls that were discovered were natural pearls.

Today natural pearls are very rare, and are often sold at auctions in New York, London and other international venues at investment prices. Natural pearls are, by definition, all types of pearls formed by accident, without human intervention. They are the product of chance, with a beginning that is an irritant such as a burrowing parasite. The chance of this natural occurrence is very slim as it depends on unwelcome entry of foreign material that the oyster

is unable to expel from its body.

A cultured pearl undergoes the same process. In case of natural pearl, the oyster is working alone, whereas cultured pearls are the products of human intervention. To induce the oyster to produce pearl, a technician purposely implants the irritant inside the oyster. The material that is surgically implanted is a piece of shell called Mother of Pearl.

This technique was developed by the British biologist William Saville-Kent in Australia and brought to Japan by Tokichi Nishikawa and Tatsuhei Mise. Nishikawa was granted the patent in 1916, and married the daughter of Mikimoto Kokichi. Mikimoto was able to use Nishikawa’s technology. After the patent was granted in 1916, the technology was immediately commercially applied to Akoya pearl oysters in Japan in 1916. Mise’s brother was the first to produce a commercial crop of pearls in the Akoya oyster.

Mitsubishi’s Baron Iwasaki immediately applied the technology to the South Sea pearl oyster in 1917 in the Philippines, and later in Buton, and Palau.

Mitsubishi was the first to produce a cultured South Sea pearl – although it was not until 1928 that the first small commercial crop of pearls was successfully produced.

Imitation pearls are a different story altogether. In most cases, a glass bead is dipped into a solution made from fish scales. This coating is thin and may eventually wear off. One can usually tell an imitation by biting on it. Fake pearls glide across your teeth, while the layers of nacre on real pearls feel gritty.

The Island of Mallorca in Spain is known for its imitation pearl industry. There are eight basic shapes of pearls: round, semi-round, button, drop, pear, oval, baroque, and circled. Perfectly round pearls are the rarest and most valuable shape. Semi-rounds are also used in necklaces or in pieces where the shape of the pearl can be disguised to look like it is a perfectly round pearl. Button pearls are like a slightly flattened round pearl and can also make a necklace, but are more often used in single pendants or earrings where the back half of the pearl is covered, making it look like a larger, rounder pearl.

Drop and pear-shaped pearls are sometimes referred to as teardrop pearls and are most often seen in earrings, pendants, or as a center pearl in a necklace. Baroque pearls have a different appeal; they are

often highly irregular with unique and interesting shapes. They are also commonly seen in necklaces. Circled pearls are characterized by concentric ridges, or rings, around the body of the pearl.