Because of the rarity of naturally occurring pearls, a process of cultivating pearls was introduced in the early 1900s. In this process, a small bead of polished shell is inserted into an oyster or mollusk to act as an irritant and produce a pearl, which can take up to 24 months. These pearls are referred to as cultured pearls. Pearls are classically elegant and never go out of style.
Akoya: Predominantly produced by Japan and China, Akoya pearls were the first pearls to be cultured. They are consistently round, which makes them perfect for strands. Colors range from white to cream, though some can be pink, gray or black.
Freshwater: The freshwater pearl is usually slightly less round, smaller in size, and possesses less luster than varieties of saltwater pearls. These pearls are usually cultivated in China and provide a value-priced option.
Mabé: Instead of growing inside an oyster or mollusk like other pearls, the mabé pearl actually grows against the shell of the oyster, creating a dome-shaped pearl. This pearl is harvested, then assembled. The nucleus is removed and replaced by resin, while mother-of-pearl is used to cover the flat back. Mabés traditionally have high luster and lower prices than round pearls.
South Sea: These pearls are cultured in the northern waters of Australia, Indonesia, and the Philippines. They are considerably larger than Akoya pearls and much more sensitive during the cultivation process. South Sea pearls are naturally white, cream, or golden in color.
Tahitian: As the name implies, these pearls are cultured in Tahiti. Of similar size to South Sea Pearls, Tahitian pearls naturally occur in black, silver, and gray.
Pearls are produced in a variety of colors, as noted in the types of pearls. Most range from white to cream, yellow to pink, silver, and black. Most pearls have both a primary color, the first color you will notice, and a secondary color, the overtone seen when you take a closer look. Color variation does not decrease the value of the pearl, but is important when matching pearls to be used in strands, earrings, bracelets, etc.
A pearl's luster is the result of multiple layers, also called the nacre (NAY ker), that the oyster or mollusk secreted to make the pearl. The thicker the nacre, the more luster a pearl has. You will notice the luster as the deep sheen that reflects light on the surface of the pearl.
Pearls come in a variety of different shapes. The most coveted of these is round. Akoya, Tahitian, and South Sea pearls are most often the roundest of the pearls. Other shapes can make beautiful jewelry as well, sometimes providing you with different price options.
Because pearls rely on an uncontrollable environment in which to grow, very rarely will you find a perfect pearl. The surface of a pearl may not always be smooth and often include very tiny spots, bumps, etc. An expert jeweler knows how to show off the beauty of pearls during the stringing and setting process.
The size of the oyster or mollusk that a pearl is produced within has aa direct effect on the size of the pearl. Size alone does not greatly impact the price of a pearl. Combined with a perfectly round shape and beautiful luster, the value will dramatically increase.