Last Friday I wrote about keshi pearls. The article reminded me of how complex the pearl market can be and it inspired me to break it down into bite sized pieces. This post covers the basics of natural pearls. Future posts will get into different types of pearls and various culturing processes.
What are pearls, anyway? The snarky answer is: solid evidence of an irritated oyster. The scientific answer is: layers of aragonite platelets bound together by conchiolin.
Where to start?
How about the thing that's irritating our oyster. A piece of sand gets into the oyster shell. The oyster can't spit it out or scratch so it coats the particle with something smooth - nacre.
Nacre is a combination of conchiolin and aragonite. Aragonite is the crystal form of calcium carbonate. Conchiolin is a substance similar to hair or fingernails that binds the crystals together.
Pearls grow a bit like trees - in layers. Some years produce beautiful, thick layers, some years aren't so pretty. The color, layer thickness and texture vary between oyster types and environments.
Over time, the pearl gets larger. The final diameter depends on the size of the oyster it's irritating. Shapes also vary.
And now for some cultured, probably freshwater, pearl jewelry from our fabulous artists: