Pearl

(purl)

 HISTORY and LORE

• Since the dawn of human culture, counted among the most beautiful and magical gems. Early hunter-gatherers probably discovered pearls during their search for food. In the ancient world, pearls had the greatest value of all material things.
• For centuries people in Asia believed pearls begin with drops of divine moisture that fall from dragons in the sky. When the drops land in seashells and are nourished by moonbeams, they grown into pearls.
• Due to their appearance and origin, pearls have always been associated with the moon and water. From these natural links they grew to symbolize purity and love.
• Birthstone for June. Gem for the 3^rd and 30^th wedding anniversaries.

NATURAL vs CULTURED

• Natural pearls are produced by about two dozen kinds of mollusks (including certain oysters, mussels, and other shellfish) – without human help of any sort.
• Cultured pearls combine Nature’s creativity with human art and science. Today almost all pearls are cultured.

VALUE FACTORS

Pearls have a unique set of value factors:

• Size: Measured in millimeters, and depends largely on type. Fine pearls near the top of the size range for their type command premium prices.
• Shape: Main categories are spherical (round and near-round), symmetrical (oval, button, drop, etc), and baroque (irregular). Round pearls are generally most expensive.
• Color: Traditionally thought of as white, but covers a wide range. Besides basic bodycolor, may also include blush-like overtone and the iridescent effect known as orient.
• Luster: The sharpness of light reflections from the pearl’s surface. Different types of pearls have differing potentials, but lust is always a critical element of beauty.
• Surface: Freedom from blemishes such as bumps, spots, and scratches. Almost all pearls have some of these characteristics. Unless unsightly or threatening they’re usually considered acceptable.
• Nacre: The thickness of the pearl’s coating. Lasting beauty and value depend on this hidden factor.
• Matching: A key consideration for necklaces, this normally means the pearls look alike in size, color, and other aspects of appearance.

PEARL TYPES

• Akoya – The most popular and familiar pearls. Produced mainly along the coasts of Japan and China, Akoyas usually range from about 4 to 8 millimeters. Rounds and near-rounds are readily available. Typical colors are white and cream, but others include pink, yellow, blue, and gray. Common overtones are rose (pink) and green. Luster can be nearly mirror-like.
• South Sea – The rarest and most expensive pearls. Grown primarily in the warm waters around Australia, Indonesia, and the Philippines, South Sea pearls are prized for their large sizes – normally 8 to 18 millimeters. Shapes are often “circled” with parallel ridges. Colors run from white and cream to silver gray, golden yellow, rosé pink, and peacock blue. Overtones include rose, green, and blue. Luster tends to be satiny rather than high-gloss.
• Tahitian – Most of these exotic-looking pearls come from the islands of French Polynesia. The Cook Islands, which belong to New Zealand, are another source. Tahitian pearls have about the same size range as South Sea cultured pearls, and “circled” shapes are common. Luster can be almost metallic. Palette includes silver gray, golden yellow, bronze, copper, deep “cherry” red, yellow-green “pistachio,” and purple-green “aubergine” – often with striking overtones.
• Freshwater – The most affordable cultured pearls, these offer a wide assortment of sizes, shapes, and natural as well as treated colors. Streams, rivers, and lakes in China are the main sources. Others come from Japan and the US.

TREATMENT

For Akoyas and most freshwater pearls, a standard step is bleaching to lighten color and eliminate dark spots. Akoyas are sometimes tinted by dye or irradiation, and similar methods produce many colors of freshwater pearls. South Sea pearls many be dyed “golden” yellow. The effects of these treatments are usually permanent, and they create no added special care requirements for gem owners.

GEMOLOGY

• Classified as an organic gem. Others in this group include amber, coral, and shell.
• Akoya, South Sea, and Tahitian pearls consist of a shell bead nucleus coated with nacre. The nacre is secreted by the mollusk, and it’s mainly composed of microscopic calcium carbonate crystals (chemical formula CaCO₃). The nucleus accounts for most of the size and weight, but the nacre provides the beauty.

CARE

Pearls need gentle wear and care.

• Hardness: Low scratch resistance. Rates 2.5 to 4 on the Mohs Hardness Scale.
• Toughness: Usually good resistance to breaking, but nacre can be chipped or broken fairly easily.
• Stability: If dyed, color may eventually fade. Nacre may also develop cracks as a result of age or exposure to dry conditions or intense light. All pearls are easily attacked by even mild acids and also many household chemical, including solvents, cleansers, alcohol, and cosmetics.
• Cleaning: NEVER USE LIQUID CLEANER OR AN ULTRASONIC. For routine cleaning, wipe pearls with a soft cloth after each wearing. Detergent and water are safe for occasional cleaning, but use a soft-bristle brush to avoid scratching. Never immerse a necklace. Pearl necklaces should be restrung every few years if they’re worn frequently.