Pearls are a beautiful biproduct of a natural mechanism that occurs when mollusks have foreign material present inside them. The mollusks coat the foreign body with calcium carbonate, and over time, the layers form a pearl. The largest pearl ever discovered was brought up by an unknown diver from the Philippines in 1934, and weighed in at an astonishing 14 pounds. It is estimated to be worth forty million U.S. dollars today, and represents one of the most expensive naturally produced single finds in the history of mankind.
The amount of lustre a pearl displayed is dependent upon the number and thickness of translucent layers deposited on the outer surface of the pearl. These layers are known as ?nacre?. The thinner and more numerous the layers, the more substantial the luster, in general. Pearls are most often white in color, although several other hues can be found as well. These range from a pinkish cream to black. Pearls can also be dyed, though fine pearls are rarely altered in any way.
Most of the pearls sold today are cultured,which means they are produced naturally with a little help from modern science. Instead of searching for the rare mollusk that might contain a pearl, pearl farmers implant a foreign substance into the mollusks they raise. This will eventually become a pearl. Unfortunately, some pearl farmers implant large foreign bodies into the mollusks to create larger pearls faster. These pearls contain very few layers of nacre and consequently, don't offer the depth that properly cultivated pearls provide. Cultivated pearls are more often than not superior to natural pearls for jewelry making, as they exhibit great proportionality and less flaws than their completely wild counterparts. Few who appreciate the beauty of pearls are familiar with the time it takes to produce a cultured pearl, much less a natural pearl.
Black Tahitian pearls are cultured from black pearl oysters, though the process is more difficult than cultivating pearls from white pearl oysters, which makes them highly sought after. Only the South Sea pearls hold a higher value as they are in less abundance. South Sea pearls come from Pinctada Maxima oysters, which are extremely rare.
