Pearl Facts
Pearls consist of calcium carbonate or CaCo3 held together buy conchiolin, the organic substance that forms the outer layer of an oyster shell. The pearl's outer coating is called nacre, a lustrous, smooth surface built up in many layers over time. A pearl is very soft with a hardness of 2.5 to 4.5 so it is easily damaged by dropping or contact with harder substances, perfume, skin oils, or cosmetics. You should clean your pearls with a soft cloth every so often. Keep them away from dust and dry heat when not wearing them.
Pearl mania reached its height during the Roman Empire. Cleopatra wagered Marc Anthony that she could serve the world's most expensive meal, whereupon she crushed a huge pearl and added the powder to wine which she drank. He conceded.
Unlike gold, gemstones, and other precious substances, the pearl arrives in perfect condition ready for use.
The priceless Merman Pendant in the Victoria & Albert museum, London, contains a huge pearl that may have come from a 100-year-old oyster.
Natural Pearls vs. Cultured Pearls
A natural pearl is an accident. A speck of foreign matter--a grain of sand, a microscopic sea creature--lodges in certain internal parts of an oyster or mussel. The oyster deposits layers of nacre in order to make the foreign matter harmless.
Until the end fo the 19th century, the only pearls on the market were naturals, and they were priceless, reserved for royalty and extremely wealthy people. Queen Elizabeth I of England swathed herself in pearls. It is rumored that she had Mary Queen of Scots executed in order to obtain Mary's pearls.
A perfect 6mm (1/4 inch) pearl would take about 5 years to form. The larger the pearl, the longer it takes to form. Millions of pearls have been lost because no one dived for them.
Cultured pearls result from the intentional implanting of a grain of sand or nucleus of pearl shell or an actual pearl into the living oyster. This is called nucleation. The oysters are then suspended in water (fresh or salt) so they can start making the pearl.
Not every oyster can produce a gem pearl. Centers for pearl culturing are Japan, Australia, China, and Polynesia.
