Clam pearls, often referred to as “quahog pearls,” are rare and naturally occurring pearls that can be found in certain types of clams, particularly in quahog clams (Mercenaria mercenaria). Quahog clams are bivalve mollusks that inhabit the Atlantic Ocean, primarily along the eastern coast of North America.These pearls are not to be confused with traditional pearls, which are formed inside oysters and other mollusks. Clam pearls are concretions of calcium carbonate, formed as a response to irritants or foreign objects that make their way into the clam’s soft tissue. Over time, the clam secretes layers of nacre (the same substance that makes up the lustrous coating of traditional pearls) around the irritant, slowly forming a pearl.