A cultured pearl is created by an irritant, such as a grain of sand, being inserted into an oyster. The oyster reacts to the irritant immediately by beginning to coat it with an organic secretion composed of calcium carbonate and conchiolin, called Nacre. (The oyster uses this same substance to create the layers of its shell.) The thicker the layers of Nacre are, the more beautiful and iridescent the pearl is. Nacre thickness determines a pearl’s longevity – the thicker the nacre, the longer the life of the pearl; the thinner the nacre, the shorter it’s life.
A pearl has two factors that determine its overall color; Body Color and Overtone. Body Color is the base color of the pearl; such as white, cream, black, or gold. Overtone is the presence of a secondary color or tint; such as pink, rose, peacock, silver or blue. It is the combination of the Body Color and Overtone that creates the overall pearl color.
A helpful way to think of a pearl’s surface is to imagine your own skin. Just as your complexion is rarely free of little imperfections, so it is with the surface of the pearl.
Dark spots, small indentations, blisters, cracks, spots and bumps all affect the value of a pearl. While some slight flaws are acceptable, the fewer of these imperfections a pearl contains, the higher its overall worth.
Pearl shapes fall into three categories: spherical, symmetrical and baroque. The rarest and most valuable of these is the spherical or perfect round shape. Because a pearl is an organic product created by a living creature, it is very rare for the shape to be perfectly round. (If only oysters took instructions!) Teardrop or pear shapes are examples of the symmetrical pearl shape. Baroque pearls have irregular shapes such as oval or eggplant.
The larger the pearl, the greater the value and the more excessive the cost. Different sizes are considered smaller or larger depending on the pearl type. For example, 8mm would be considered very large for the Akoya pearl, while 8mm is considered to be small for the South Sea pearl. Here are some general size ranges for the four types of pearls:
Akoya = 6-9mm
Tahitian = 8-12mm
South Sea = 8-13mm
Freshwater = 5-11mm
Taking proper care of your pearls is important for their longevity and value. Here are some quick care tips:
-Avoid contact with harmful substances. Vinegar, ammonia, chlorine, bleach, ink, hairspray, make-up and perfumes are all harmful to a pearls’ overall health. Make sure to apply any and all cosmetics BEFORE you put on your pearls.
-Store separately. It is wise to keep your pearls in a separate jewelry case as to prevent scratching from sharp metal edges or prongs, or against harder stones. Never toss pearls carelessly into your purse or suitcase. Do not keep them in a airtight container, as pearls require moisture and sealed containers can dry them out. Store them in something with a soft lining, such as satin or silk.
-Clean after each use. After wearing your pearl jewelry, wipe them gently with a warm, damp towel before putting them away to remove skin oil and sweat. Do not use any kind of cleaning agent or detergent, as this may damage your pearls.
-Periodic washing is recommended. Wash your pearls from time to time using a soft cloth in warm, sudsy water using a mild soap. After washing, rinse them in clear water and then wrap them in a clean, thin, damp cotton towel to dry. When the towel is dry, the pearls will be dry.
-Restring your pearls periodically. If you wear your pearls often, having them restrung once a year is recommended. Pearls should only be strung on silk, with a knot in-between each pearl.
Pearls come in four varieties; Akoya, South Sea, Tahitian and Freshwater.
Akoya pearls come from the Akoya oyster (Pinctada fucata martensii) and are found in the seas of Japan. They are famous for their white, silver and rose tones, and are considered the traditional, classic pearl.
South Sea pearls originate off the coast of Australia and are found in the Pinctada maxima oyster. They are renowned for their golden glow, but can also come in a bright silver tone. They are considered very luxurious.
Tahitian pearls are harvested from the seas of Tahiti. They are what people mean when they refer to “black pearls”. Their deep black color combined with rich peacock or green overtones gives them an exotic look.
Freshwater pearls are grown in freshwaters such as lakes and ponds, as opposed to saltwater seas and gulfs. Like the Akoya, their colors range from white, silver, cream and pink. They are known for their affordability while maintaining a large size.