Natural pearls are among the rarest and most valued of fine gems. American freshwater pearls have a history thousands of years old and played a particularly prominent role in the jewelry of the late 19th and early 20th centuries. Today, though a fraction of its original size, the American freshwater pearl industry continues to produce fine material for the jeweler worldwide. The source of this pearl is the Unio mussel, fished by brailing boats and intrepid divers from the rivers and lakes of America. From the Unio in which it grows, the American freshwater pearl derives its distinctive shapes and colors. A new entry to the American pearl industry is the freshwater cultured pearl, illustrated in this article for the first time ever. -- AATA