While natural pearls are extremely rare, cultured or farmed pearls are more common. In fact, they make up the vast majority of pearls on the market today. Cultured pearls are formed in exactly the same way, but with the irritant (usually a tiny bead) purposefully placed inside the oyster’s shell by humans.
Farmed in rivers, lakes and ponds, freshwater pearls are most common as they take less time to cultivate, and each oyster can make up to 30 at a time. Saltwater pearls, on the other hand, fetch higher prices as they take longer to form and can only be grown one at a time. Mostly grown around Australia and Asia, the three main types are South Sea pearls, Tahitian pearls and Akoya pearls.