Pearls of all types form as a reaction to an irritant inside the shell of mollusks like oysters and mussels. The mollusk reacts to the irritation by secreting a substance known as nacre, which is also used in shell-building. In time, the nacre builds up to form a pearl. When this happens in nature, a natural pearl is created. When a technician introduces an irritant into the shell of an oyster or mussel, however, the resulting pearl is referred to as “cultured.” The Japanese first cultured true pearls using freshwater mussels. A man named Kokichi Mikimoto is credited with perfecting the technique of culturing freshwater pearls through experiments conducted by him and his associates in 1920 at Lake Biwa, which is a large lake located near Kyoto. They seeded mussels using only soft mantle tissue, which resulted in an all-nacre pearl with an unusual shape and nice luster. T
There are over 160 drilled Biwa pearl beads in this group - more than enough to make several necklaces.
They are between ⅝" - 1" in size.