Monday, April 13, 2009

A little story of Pearls

Some believed pearls to be the tears of the gods. Others thought them dewdrops filled with moonlight that fell into the ocean and were swallowed by oysters.




A pearl is a natural gem created by a living organism. When a foreign object is introduced into a mussel or oyster the animal coats the irritant with a substance called nacre, the same material with which it builds it’s shell. Over time, the layers of nacre build up to form the pearl. The longer the irritant remains in the mollusc, the more layers of nacre and (usually), the better the pearl.




Each pearl must be sorted by size, shape, colour, lustre and blemish. Then they need to be drilled and matched for stringing - a skilled task.




Nacre is not just a soothing protection for the mollusc. It’s made of tiny crystals of calcium carbonate, perfectly alligned with each other, so that light passing along the axis of one is reflected and refracted by the other to produce a rainbow of light and colour.




Seawater Pearls have a round shell bead (usually from an American freshwater mussel) inserted as the irritant. This is refered to as ‘nucleating’.

Freshwater Pearls have a piece of mantle tissue (nacre producing tissue from another mussel) introduced as the irritant. Freshwater pearls are non-nucleated.







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