There are four different types of pearls: Akoya, Freshwater, South Sea and Tahitian.
The four main types of pearls are listed below.
These are the type of pearl that are produced by the Akoya oyster in the cooler waters of Japan and China. These pearls usually range from 2mm to 10mm and range in color from blue, green, pink, rose, cream, white, silver and gold. Akoya pearls are most recognized for their high luster, and their richness of color.
These are the type of cultured freshwater pearls mostly from China made in a freshwater in a lake, pond or river, in Hyriopsis Cumingi mollusks. In each host, ten to fourteen pearls can be cultured at one time. They are similar in look to the Akoya pearls, but are less expensive because they are generally smaller and less symmetrical. These pearls typically come oval-shaped, or in rice grain shapes.
Cultured pearls produced by the black-lip oyster (Pinctada Margaritifera) found in the atolls and lagoons of French Polynesia. Black Tahitian pearl is darker and larger. They are very unique and expensive because of the complicated cultivation process. Tahitian pearls range in color from black, gray, silver, green, orange, gold, blue and purple. The black body colors has green or pink undertones. Black Tahitian pearl, also known as the Queen of Pearls, ranges from 11-12mm in diameter.
South Sea Pearls
South Sea pearls are formed by oysters called Pinctada Maxima, which live in the warmer waters of the South Seas, as well as off the coast of Australia, the Philippines, and Indonesia. These fascinating pearls are known to be quite large, average South Sea pearls range from 11-13mm in diameter. South Sea pearls have unique colors which depend on the specific type of oyster in which they’re grown. South sea pearls are harder to cultivate and therefore more expensive. South sea pearls are the biggest and most expensive on the market.
Pearls are also classified in 3 categories: natural, cultured, and imitation pearls.
Natural pearls are those which have been created as an accident within oysters and mussels in the “wild”. Humans will not have had any part of their formation. However, natural pearls are now extremely rare in the market and are seldom seen at most jewellers.
Cultured pearls are formed inside a living oyster with human intervention, by the insertion of a small shell bead inside the tissue of a mollusk. Then the nucleated oysters are quickly returned to the sea. After the mollusk coats the intruder with a pearly secretion (nacre) to cut the irritation to its body, the mollusks are opened carefully, and the cultured pearl removed. Cultured pearls are the most desired today, for their cost and beauty is within the reach of everyone.
Imitation pearls can be made of many different substances such as glass, plastic, and even shell, which are formed into spheres, and polished with items such as lacquer, fish scales, or plastic, for that pearly finish. It takes only a 10x lens to identify if they are imitation pearls.