Natural pearls form when a grain of sand, parasite or some other foreign matter enters the body of a pearl-producing mollusc. This foreign matter or object scratches and irritates the mollusc. The oyster’s natural reaction is to cover up that irritant to protect itself. The mollusc deposits layers of nacre (mother of pearl) over the intruder to soothe the irritation. This eventually forms a pearl.
What are Cultured Pearls?
Cultured pearls are real pearls that have been given a helping hand by man. Instead of a parasite or some other foreign matter entering the body of a pearl-producing mollusc, man has helped the process along by inserting the irritation. The mollusc deposits layers of nacre (mother of pearl) over the intruder to soothe the irritation. This eventually forms a pearl.
Saltwater Cultured Pearl
Saltwater cultured pearls form when a bead nucleus and a piece of mantle tissue are inserted into the mollusc. This process is called bead nucleation. These pearls are usually the rounder shaped pearls.
Freshwater Cultured Pearl
For freshwater cultured pearls, there are two processes that are used. The first culturing process starts when only a piece of mantle tissue (no bead) is inserted into the mollusc (usually a muscle). This is called tissue nucleation. The mollusc reacts to the irritant, the intruding tissue, in the same manner as with bead nucleation. Tissue-nucleated pearls are almost entirely nacre. These pearls are more commonly known as rice pearls.
The second culturing process is bead nucleation. The result is a pearl that looks similar to saltwater cultured pearls.
Different types of Cultured Pearls
Today’s cultured pearl jewellery market includes a wide range of products.
- Freshwater pearls are found in a large range of sizes, shapes, and colours. China is the primary source for today’s freshwater pearls. Japan and the United States produce small crops.
- These are saltwater pearls cultivated primarily in Japan and China. Most Akoya pearls have a white to cream body colour. Other natural colours, including yellow, grey, and blue.
- South Sea
- Australia, Indonesia, and the Philippines are the principal areas for commercial farming of these saltwater pearls. They typically range in colour from white to golden. Other colours do occur.
- Are cultivated primarily around the islands of French Polynesia, these saltwater pearls range in colour from white to black to other colours, including green and purple.
- Mabé pearls grow attached to the mollusc’s shell. A nucleus (bead) is attached to the shell, as with pearls this irritates the mollusc, and it is covered by a thin layer nacre. The mabé are then cut out around the nucleus. The nucleus is then removed. The resulting void is filled with epoxy resin (and sometimes a bead) and glued to a mother-of-pearl backing. A Mabé is very delicate, the slightest bump can cause the thin layer of nacre to come off or crack, leaving the epoxy resin or bead exposed. It can happen that some of these components separate for one or other reason, probably through wear & tear, heat or something. If you still have the part that came loose it might be able to be repaired, the only other option is to replace the mabé.
- Blister pearls are mabe pearls (see above), but instead of cutting it out directly around the nucleus, it is cut out in a free formed shape.
- Pearl appears round.
- Pearl slightly elongated or flattened.
- Pearl appears symmetrical, rounded & oblong.
- Pearl appears symmetrical, rounded & flattened.
- Pearl appears symmetrical, rounded & pear shaped.
- Pearl appears to have no apparent symmetry; irregular in shape.
- Pearl appears not quite symmetrical; off-round and/or slightly irregular drop, button, or oval shape.
- Any non-standard shape. For example: cross, bar, coin.
- Circled (Modifier)
- One or more grooved or ridged rings around the circumference of any shape pearl.
Care and Cleaning
Pearls are more delicate than most gem materials, so they require special care. Store pearls in a soft pouch or separate container to minimize contact with other jewellery.
- Clean pearls regularly with a soft, damp cloth or lambskin chamois.
- Periodically clean pearls in a solution of warm water and non-detergent soap; lay pearls on a clean towel and dry completely before wearing.
- Periodically restring strands of pearls. The silk string should be clean, the knots should be tight, and there should be no slack between the knots and pearls.
- Never ultrasonic or steam-clean pearls.
- Use only commercial jewellery cleaners that are made specifically for pearls. Caution your customers to remove pearl jewellery before they:
- Apply cosmetics, perfume, or hair spray
- Swim in chlorinated pools
- Wash dishes, do housework, or do gardening
- Do strenuous work or exercise