Pearls are formed inside the body of oysters. The mollusk deposits layer of nacre, a combination of crystalline and organic substances, when any irritant or parasite enters or placed inside its body. Over a period of time with nacre building up in layers and layers, the pearl is formed.

All the pearls sold in USA and in other countries around the world are cultured pearls and are known by various names such as freshwater pearls, akoya seawater pearls etc. Natural pearls are rarity.

The bead-nucleating technology of producing cultured pearls was developed and perfected by Kokichi Mikimoto of Japan in early 20th Century. Japan is famous for producing akoya cultured pearls but recently China has become the leading source of all cultured pearls - freshwater and akoya pearls.

Difference in cultured and natural pearls can’t be made with naked eyes; however, distinction becomes very prominent when seen through x-rays. Cultured pearls are used in pearl jewelry as well as in cosmetics. One should also be careful about imitation pearls.

Cultured pearls are generally in white colors but can be colored-dyed in various colors.