Pearls can be natural or cultured and are formed from nacre a substance created by the Pearl Oyster. Nacre is a combination of the mineral Aragonite and a protein called conchiolin. Most pearls used in jewellery are cultured as natural pearls are extremely expensive.
Oyster beds are found in the Pacific and Indian oceans and are an important source of livelihood for the island communities. The oysters health and ability to produce pearls and the nacre on their shells depends on a healthy ecosystem with a good biodiversity so it is in the interest of the pearl farmers to maintain the purity and diversity of the marine environments. Oysters themselves act as a natural cleaner as they filter impurities from the ocean waters. In 2014 Sustainable Development Goals were developed for the Pearl Industry by the UN. Australia still allows the catching of wild oysters , but under a strict quota system and with a limited number of permits being issued.
The first cultured pearls were created in Japan in 1893. Cultured pearls are formed when minute pieces of sand grains are inserted into the oyster . The mollusc responds by coating the grains with several layers of nacre . This then forms the pearly layers which can be identified if the pearl is cut open .
Pearls were known in China as far back as 2000 B.C. The Romans valued them as a status symbol. Legend states that they were formed from dewdrops which were swallowed by oysters as they fell into the sea. A lovely thought !
They are a birthstone for Gemini and Cancer. They are a symbol of femininity , fertility and longevity.