Freshwater pearl mussel Freshwater pearl mussel The freshwater pearl mussel ("Margaritifera margaritifera") is an endangered species of freshwater mussel, an aquatic bivalve mollusc in the family Margaritiferidae. Although the name "freshwater pearl mussel" is often used for this species, other freshwater mussel species can also create pearls and some can also be used as a source of mother of pearl. In fact, most cultured pearls today come from "Hyriopsis" species in Asia, or "Amblema" species in North America, both members of the related family Unionidae; pearls are also found within species in the genus "Unio". The interior of the shell of "Margaritifera margaritifera"
Parable of the Pearl writings. Pope Pius XII used the phrase to describe virginity. The pearl itself is a beautiful, single entity, formed through suffering in the heart of the oyster (in the same way that believers endure lack of wealth or comfort) and like the Church, will be put on display in a coming day. Unlike precious stones which must be cut and polished to reveal their clarity and beauty, the pearl is perfect as it comes from the oyster. A version of the parable also appears in the Gnostic Gospel of Thomas (Saying 76): This work's version of the parable of the