Types of Pearls
Akoya
These pearls were the first type of pearl to be cultured. These are high-end Japanese saltwater pearls. You may also find Chinese Akoya pearls, which are somewhat less desirable than Japanese Akoya. Akoyas are consistently round, which makes them perfect for strands. Colors range from white to cream, though some can be gray or black.
Freshwater
The freshwater pearl is usually slightly less round, and possesses less luster than varieties of saltwater pearls. These pearls are usually cultivated in China and provide a value-priced option, as freshwater pearls can be grown much more quickly than other pearl types. This is the most common pearl. Attractive freshwater pearls can represent an excellent value.
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. These pearls 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. When high quality, these pearls can be very valuable.
Tahitian
These pearls are slightly smaller than the South Sea pearl, but larger than Akoyas. They are also sensitive during the cultivation process. The colors of black, silver, and gray occur naturally and they are cultured in Tahiti as their name implies.
Color
Pearls are produced in a variety of colors, as noted in the types of pearls. Most range from white, cream, and yellow to pink, silver, and black. Most pearls will have both a primary color, the first color you will notice, and a secondary color, the overtone you notice 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.
Luster
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.
Shape
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.
Surface
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, often including spots, bumps, etc. The beauty of these pearls may be enhanced by the ability to sometimes be camouflaged during the stringing and setting process.
Size
The size of the oyster or mollusk that a pearl is produced within will have a direct effect on the size of the pearl. The size alone may not greatly impact the price of a pearl, but when you combine it with a perfectly round shape and beautiful luster, the value will dramatically increase.