Pearls are highly valued gemstones. Pearls are formed by mollusks when a foreign particle penetrates the mantle, the cells attach to the particle and build up more or less concentric layers of pearl around it.
The color of pearls varies with the mollusk, and its environment. It ranges from black to white. Other colors are cream, gray, blue, yellow, lavender, green, and mauve. All occur in delicate shades. Cultured pearls are produced in virtually every color of the rainbow.
Pearl is said to help one see oneself and help improve self-worth as an emblem of modesty, chastity, and purity. The pearl symbolizes love, success, and happiness.
Freshwater mussels in the temperate zone of the Northern Hemisphere have produced pearls of great value, as an example those from the Mississippi River. Pearling is a carefully fostered industry in central Europe, and the forest streams of Bavaria, in particular, are the source of choice pearls. Freshwater pearling in China has been known from before 1000 BC..