What is Pearl?
[[File:White pearl necklace.jpg|thumb|200px|A white pearl [[necklace]].]] '''Pearls''' are made of a kind of material made by [[Mollusca|mollusks]], like [[oyster]]s. Pearls are small and often white but sometimes in pale colors or even black. They are often round, but sometimes half-round, oval, or in different shapes. Pearls are often used for [[jewelry]]. The pearl is the birthstone for the month [[June]]. == How a natural pearl is formed == A natural pearl is formed when nacre-producing cells are displaced from the mantle tissue of an oyster. These cells are genetically programmed to produce nacre, the substance that lines the inner sides of an oyster's shell. When the cells become displaced, often by a boring parasite or damage to the outer shell, they continue to do what they are programmed to do -- produce nacre and form a pearl. They can be very tiny (as tiny as a [[peppercorn]]) or quite big (as big as a human's [[wikt:fist|fist]]). The world's largest pearl, found in 1934 and called the Pearl of Lao-tze, is about the size of a basketball. == Types of pearls == There are two kinds of pearls: [[Salt water|saltwater]] pearls and [[Fresh water|freshwater]] pearls. Saltwater pearls come from [[oyster]]s that live in the [[oceans]]. Freshwater pearls are found in [[mussel]]s that live in [[rivers]], [[lakes]], or [[Pond|ponds]]. <ref> ''Exploring Creation with Zoology 2'' by Jeannie K. Fulbright p. 147 </ref> There is also a ''natural pearl'' and a ''cultured pearl.'' Natural pearls are made by oysters accidentally, and are very rare. Cultured pearls are made by inserting small [[wikt:bead|beads]] and a piece of donor mantle tissue (in the case of saltwater pearls) into the reproductive organ of a saltwater oyster, or simply inserting a piece of donor mantle tissue (in the case of freshwater pearls) into a small incision in the mantle of a freshwater mussel. == References == <references/> {{commonscat|Pearls}} {{sci-stub}} {{Jewellery}} [[Category:Gemstones]] [[Category:Birthstones]]