Perhaps the best-loved gems of all time, pearls—natural and cultured—occur in a wide variety of colors. The most familiar are white and cream, but the palette of colors extends to every hue. Produced in the bodies of marine and freshwater mollusks naturally or cultured by people with great care. Lustrous, smooth, subtly-colored pearls are jewelry staples, especially as strands
Perhaps the best-loved gems of all time, pearls—natural and cultured—occur in a wide variety of colors. The most familiar are white and cream, but the palette of colors extends to every hue. Natural pearls form around a microscopic irritant in the bodies of certain mollusks. Cultured pearls are the result of the deliberate insertion of a bead or piece of tissue that the mollusk coats with nacre.
Perhaps the best-loved gems of all time, pearls—both natural and modern cultured pearls—occur in a wide variety of colors. The most familiar colors are white and cream (a light yellowish brown). Black, gray, and silver are also fairly common, but the palette of pearl colors extends to every hue. The main color, or bodycolor, is often modified by additional colors called overtones, which are typically pink (sometimes called rosé), green, purple, or blue. Some pearls also show the iridescent phenomenon known as orient.
Cultured pearls are popular for bead necklaces and bracelets, or mounted in solitaires, pairs, or clusters for use in earrings, rings, and pendants. Larger pearls with unusual shapes are popular with creative jewelry designers.
Pearl—natural or cultured—is a US birthstone for June, together with alexandrite and moonstone.
Natural pearls form in the bodies, or mantle tissue, of certain mollusks, usually around a microscopic irritant, and always without human help of any kind.
The growth of cultured pearls requires human intervention and care. Today, most of the mollusks used in the culturing process are raised specifically for that purpose, although some wild mollusks are still collected and used.
To begin the process, a skilled technician takes mantle tissue from a sacrificed mollusk of the same species and inserts a shell bead along with a small piece of mantle tissue into a host mollusk’s gonad, or several pieces of mantle tissue without beads into a host mollusk’s mantle. If a bead is used, the mantle tissue grows and forms a sac around it and secretes nacre inward and onto the bead to eventually form a cultured pearl. If no bead is used, nacre forms around the individual implanted mantle tissue pieces. Workers tend the mollusks until the cultured pearls are harvested. There are four major types of cultured whole pearls:
Akoya—This type is most familiar to many jewelry customers. Japan and China both produce saltwater akoya cultured pearls. South Sea—Australia, Indonesia, and the Philippines are leading sources of these saltwater cultured pearls. Tahitian—Cultivated primarily around the islands of French Polynesia (the most familiar of these is Tahiti), these saltwater cultured pearls usually range from white to black. Freshwater—These are usually cultured in freshwater lakes and ponds. They’re produced in a wide range of sizes, shapes, and colors. China and the US are the leading sources.
Pearl History and Lore
People have coveted natural pearls as symbols of wealth and status for thousands of years. A Chinese historian recorded the oldest written mention of natural pearls in 2206 BC. As the centuries progressed toward modern times, desire for natural pearls remained strong. Members of royal families as well as wealthy citizens in Asia, Europe, and elsewhere treasured natural pearls and passed them from generation to generation.
From those ancient times until the discovery of the New World in 1492, some of the outstanding sources of natural pearls were the Persian Gulf, the waters of Ceylon (now Sri Lanka), Chinese rivers and lakes, and the rivers of Europe.
During Christopher Columbus’s third (1498) and fourth (1502) voyages to the New World, he repeatedly encountered native people adorned with natural pearls. His discovery of natural pearl sources in the waters of present-day Venezuela and Panama intensified demand in Europe. However, within a hundred years, these natural pearl sources had declined due to overfishing, pearl culturing, plastic buttons, and oil drilling.
The first steps toward pearl culturing occurred hundreds of years ago in China, and Japanese pioneers successfully produced whole cultured pearls around the beginning of the twentieth century. These became commercially important in the 1920s (about the same time natural pearl production began to decline). From the 1930s through the 1980s, pearl culturing diversified and spread to various countries around the world.
Pearls are treasures from the Earth’s ponds, lakes, seas, and oceans, and they’ve always embodied the mystery, power, and life-sustaining nature of water.
The spherical shape of some pearls led many cultures to associate this gem with the moon. In ancient China, pearls were believed to guarantee protection from fire and fire-breathing dragons. In Europe, they symbolized modesty, chastity, and purity.
Few people outside the gem industry realize the true nature of a cultured pearl’s journey from the producer to the counter of a store. Whether the gem is being offered to consumer’s at a traditional jewelry store’s counter, an internet shopping site, or a television broadcast the journey always involves a great deal of effort. Careful nurturing, countless hours of labor, and significant investment are needed to being a pearl to market.
Pearl Buyer's Guide
The qualities that determine a natural or cultured pearl’s value are size, shape, color, luster, surface quality, nacre quality, and—for jewelry with two or more pearls—matching.
LUSTER Of the seven pearl value factors, luster might be the most important. Luster is what gives a natural or cultured pearl its unique beauty. Pearls with high luster have sharp bright reflections on the surface. Different pearl varieties have different standards for luster.
SURFACE If surface characteristics are numerous or severe, they can affect the durability of the pearl and severely depress its value. Surface characteristics have less effect on the pearl’s beauty and value if they are few in number, or if they are minor enough to be hidden by a drill-hole or mounting.
SHAPE Pearls come in eight basic shapes: round, semi-round, button, drop, pear, oval, baroque, and circled. Perfectly spherical pearls and symmetrical drops are the most valued. There are exceptions, though. Well-formed pear, oval, or baroque cultured pearls are also prized by pearl lovers.
COLOR Pearl body colors vary by variety. Although white and black are traditional, unusual colors are becoming more popular. Overtones in a pearl’s luster and the rainbow iridescence known as orient also add to the color of a pearl.
NACRE THICKNESS Luster and nacre quality are closely related. If the nucleus is visible under the nacre, or if the pearl has a dull, chalky appearance, you can assume that the nacre is thin. This affects the luster as well as the durability of the pearl. Nacre thickness is evaluated to make sure that cultured pearls are durable as well as beautiful.
SIZE In general, the larger the pearl, the more valuable it is. Different varieties come in different sizes: South Sea cultured pearls are the largest.
MATCHING Jewelry designers sometimes deliberately mix colors, shapes, and sizes for unique effects, but for most pearl strands, earrings, or other multiple-pearl jewelry, the pearls should match in all the quality factors.
- Featured Gem: Pearl, GIA, http://www.gia.edu/pearl