Pearls are formed when a piece of sand or other irritant finds its way into an oyster. The oyster begins to secrete a smooth hard crystalline substance called nacre around the irritant to protect itself. As long as the irritant remains, the oyster will continue to produce this nacre, layer upon layer. It will take several years to produce a 3 to 4mm pearl.
Freshwater pearls are grown in fresh water mollusks and they are more of a freeform shape than other pearls.
Some believe pearls give the wearer a sense of calmness and centeredness. Pearls promote faith, loyalty, truth and purity. They can especially enhance personal integrity and help with inspirational thought and wisdom.