How does an oyster...?

Question

Choose that one special grain of sand to make into a pearl???

Answer 1

very carefully

Answer 2

Most people think (or have heard) that a small grain of sand is responsible for the formation of a pearl, so, in order to produce a cultured pearl you got to get a grain of sand inside the oyster. This is way far from being the truth.

A natural pearl is never formed when a grain of sand gets inside the oyster. Pearl Oysters live on the bottom of the ocean, where all the sand you want can be found... they are actually capable of getting rid of sand, bits and pieces of shell, corals, and little pebbles.

The real reason behind the natural formation of a pearl lies behind a biological intruder: a parasitic organism. These may be drilling worms (polychaetes, such as Polydora), a drill-mussel (like Teredo) or many other kinds of organisms (like the drill-sponge Cliona or even the cysts of worms). When a parasite drills thru the shell of the pearl oyster, the oyster becomes irritated and uses its only means of defense to form a barrier: the mantle. This unique organ covers all the inside of the shell of the oyster and is responsible for the secretion of the pearly substance know as mother-of-pearl or nacre. The oyster will use its mantle to secrete nacre on top of these nasty intruders and, if lucky, will coat them and turn them into natural pearls. Very few natural pearls will be of good size (bigger than 8 mm) and of good quality, and those that do are able to fetch very high prices.

Answer 3

I think it just grabs the nearest sand. ;-)