Though oysters are highly prized as a seafood, the gemstones that they produce are even more valuable. In past eras, divers had to collect wild oysters and pry them open, hoping to find natural pearls inside. Pearl hunting was lucrative, but also very dangerous and tedious. Divers would often have to collect a huge number of oysters before finding a pearl. The industry now relies mainly on cultured pearls.
Pearl farms, both saltwater and freshwater, operate in natural bodies of water. The oysters are kept on strings or in baskets. Before they are placed, a trained technician performs an operation that grafts part of the oyster's mantle onto a section known as the “pearl pocket.” For saltwater pearls, a “bead” of mother of pearl is also implanted. One of the biggest expenses of pearl farming is hiring someone with the skill to perform this “surgery” successfully on each oyster. Freshwater pearls generally grow faster and the oysters can have more than one graft at a time. More-valuable saltwater pearls take several years to form, making them a more profitable, but riskier, investment.