ความเชื่อของไข่มุก เป็นอัญมณีแห่งสายน้ำ เสริมสง่าราศีให้กับเพศหญิงก่อให้เกิดความนุ่มนวล อ่อนหวาน แก้ปัญหาทางด้านอารมณ์
The most valuable pearls occur spontaneously in the wild, but are extremely rare. These wild pearls are referred to as natural pearls. Cultured or farmed pearls from pearl oysters and freshwater mussels make up the majority of those currently sold. Imitation pearls are also widely sold in inexpensive jewelry, but the quality of their iridescence is usually very poor and is easily distinguished from that of genuine pearls. Pearls have been harvested and cultivated primarily for use in jewelry, but in the past were also used to adorn clothing. They have also been crushed and used in cosmetics, medicines and paint formulations.
Cultured pearls[edit]
Main article: Cultured pearl
Nuclei from Toba Pearl Island, Japan
Cultured pearls are the response of the shell to a tissue implant. A tiny piece of mantle tissue (called a graft) from a donor shell is transplanted into a recipient shell, causing a pearl sac to form into which the tissue precipitates calcium carbonate.
There are a number of methods for producing cultured pearls: using freshwater or seawater shells, transplanting the graft into the mantle or into the gonad, and adding a spherical bead as a nucleus. Most beadless cultured pearls are mantle-grown in freshwater shells in China, and are known as freshwater cultured pearls.