A pearl is a hard, rounded object produced by certain animals, primarily molluscs such as oysters. Pearls can be used in jewelry and also crushed in cosmetics or paint formulations. Pearl is valued as a gemstone and is cultivated or harvested for jewelry. A natural gemstone is formed when an oyster is irritated by a substance that gets into its shell. If the irritation is a naturally occurring grain of sand, it is an Oriental pearl. If it is produced by purposefully inserting a mother-of-pearl bead, a cultured pearl is formed. A pearl that forms attached to the shell is a blister pearl, while a pearl that forms a half dome is a mabe (pronounced mah-bay) pearl. Pearls that are irregularly shaped rather than round are referred to as baroque.
