Pearl production occurs when a nacreous mollusk, such as an oyster or a mussel, forms a pearl in response to an irritant, like a grain of sand. The mollusk secretes layers of nacre, a substance that coats the irritant, gradually forming a pearl over time. This natural process can take several years, depending on the species and environmental conditions. In commercial pearl farming, farmers introduce irritants into the mollusks to stimulate pearl formation. The mollusks are then carefully nurtured in controlled environments, such as oyster beds or lakes. Once the pearls are fully formed, they are harvested, cleaned, and often polished for use in jewelry and other decorative items.