Most gemstones are formed in the Earth’s crust and mined from the ground. However, pearls are unusual as they come from a living creature, an oyster. This mollusk is edible and also produces mother of pearl that is used in the creation of jewelry and watch dials. The tiniest grain enters the shell and a substance called nacre is secreted to surround it. The creature inside the shell is soft and vulnerable, so must protect itself from the abrasive sand. As layers of nacre build around the grain of sand, a pearl forms. Only 1 in 10,000 wild oysters contain pearls, making them very rare and difficult to find. However, pearls can be artificially cultivated to meet the demand from the jewelry market. Only 1% of pearls used in jewelry are natural.
The earliest piece of pearl jewelry was found in the sarcophagus of a Persian Princess. It was discovered that it dates back to 520BC. The item found was a beaded pearl necklace that consists of 216 pearls in total. It is currently on display at The Louvre, Paris.
Types of Pearls
The akoya pearl is a saltwater cultured pearl from the akoya oyster (Pinctada fucata martensii). These pearls were the first type of pearl to be cultured. Japan and China are the main producers of these pearls and are consistently round, which makes them perfect for strands. Akoya are the classic pearl used for necklaces and other pearl jewelry, with perfect round shapes, bright mirror-like luster and neutral colors, akoya pearls are favored by most retailers and consumers as the classic pearl choice.
The freshwater pearl is usually slightly less round, smaller in size, and possesses less luster than other varieties of saltwater pearls. These pearls are usually cultivated in China and provide a value-priced option.
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.
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.
These pearls are slightly smaller than the South Sea pearl, but 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.
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.
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, 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.
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.