Pearl mussels live in lakes, rivers and streams. These freshwater mollusks produce pearls that can rival those of marine mollusks in luster and diverse color. And some species of freshwater pearl mussels are known to have produced dozens of pearls at a time. The local freshwater pearls of Europe, Asia and North America have been prized for hundreds and even thousands of years. In the early 1900s, the many species of North American pearl mussels supplied the thick mother-of-pearl needed for the button industry then booming in the Midwest. Today, freshwater mussel shells provide material for bead nuclei, which pearl farmers around the world implant in marine pearl oysters to create cultured pearls.
Regrettably, eastern North America has lost more than 35 species of pearl mussels to extinction in the last 50 years, chiefly from habitat destruction and pollution. Today, conservation efforts are increasing to protect the species that remain.
The necklace shown on the right includes 34 natural pearls from the River Tay, in Scotland. While imprisoned by Queen Elizabeth I, Mary, Queen of Scots, presented it to the Duke of Norfolk, who would have become her fourth husband if the marriage had taken place.