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 QUALITY FACTORS:
The qualities that determine the overall value of a natural or cultured pearl or a piece of pearl jewelry are size, shape, color, luster, surface quality, nacre quality, and—for jewelry with two or more pearls—matching.
Size: When other value factors are equal, larger pearls are rarer and more valuable than smaller pearls of the same type.
Shape: Round is the most difficult shape to culture, making it the rarest cultured pearl shape and—if all other factors are equal—also generally the most valuable. There are exceptions, though. Well-formed pear, oval, or baroque (irregularly shaped) cultured pearls are also prized by pearl lovers.
Color: Natural and cultured pearls occur in a broad range of hues. There are warm hues like yellow, orange, and pink, and cool hues like blue, green, and violet. Pearls have a wide range of tone from light to dark. Pearl colors tend to be muted, with a soft, subtle quality.
Cultured pearls can come in a variety of amazing colors. These Tahitian saltwater cultured pearls have a color intensity that’s almost like neon lights.
Pearl color can have three components. Bodycolor is the pearl’s dominant overall color. Overtone is one or more translucent colors that lie over a pearl’s bodycolor. And orient is a shimmer of iridescent rainbow colors on or just below a pearl’s surface. All pearls display bodycolor, but only some show overtone, orient, or both.
The law of supply and demand determines the value of certain pearl colors at any given time. If supplies of high-quality pearls displaying a preferred color are low, their prices can rise to unusually high levels. Other complex factors, like fashion trends and cultural traditions, can influence color preferences.
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.
- Excellent – Reflections appear bright and sharp
- Very Good – Reflections appear bright and near sharp
- Good – Reflections are bright but not sharp, and slightly hazy around the edges
- Fair – Reflections are weak and blurred
- Poor – Reflections are dim and diffused
Within a pearl type, when other value factors are equal, the higher the luster, the more valuable the pearl.
Surface quality: Like colored stones, most pearls never achieve perfection. Some might show abrasions that look like a series of scratches on the surface, or a flattened section that doesn’t affect its basic shape, or an irregular ridge that looks like a crease or wrinkle.
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.
Nacre quality: 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.
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.