A quahog is a bivalve clam native to the eastern seaboard of the United States. Used mostly as a food source, these clams occasionally produce a pearl-like gem (non-nacreous calcareous concretion) in a beautiful natural purple color. Not many of these concretions are produced; approximately 1 in 100,000 clams produces a “pearl”, and of those, very few are gem quality. Beads carved from quahog shells were known as “wampum” by Native Americans in that region and used as currency. They are still valued today.