Friday, September 2, 2011

Gemstone of the Week: Pearls

("Mared" by Handmaden Designs)

Pearls are a classic, well-loved gem.  They are made of the same nacre that makes mother of pearl, only it's formed over an irritant (often a small parasite) that gets into the mollusk.  Most pearls come from oysters, but they can also form inside of clams or mussels.  There are many different types of pearls. Some pearls are round-ish but flat on one or both sides, these are often termed "coin pearls" because of their shape; another type is the Baroque pearl.  Baroque pearls are any non-unifrom, irregularly shaped pearl.  The stranger the shape, the more valuable the Baroque pearl. 

Of the approximately 8,000 species bivalve mollusks, only 20 of the are capable of creating pearls.  Natural pearls are very,very rare and even more rare is finding a perfectly round pearl as the pearl will often take the shape of the irritant it is formed around. 

Because of how rare natural pearls are and the fact that only a fraction of these natural pearls are gem quality, most of the pearls used today are what are called "cultured pearls."  Cultured pearls are basically lab-grown pearls.  They are not fake pearls, just pearls that have been helped along by someone artificially introducing and imbedding the irritant into the mollusks tissue.  The mollusks are then placed back in the sea and the pearls are then allowed to form naturally.  Basically, it's pearl farming.  Someone plants the irritant into the mollusks and then harvests them later when they are ready.