Pearl formation is a biological process occurring within certain mollusks. When an irritant, such as a parasite or a grain of sand, enters the mollusk’s mantle tissue, the animal initiates a defense mechanism. This mechanism involves coating the irritant with layers of nacre, also known as mother-of-pearl. These layers of nacre are composed of aragonite (calcium carbonate) crystals and conchiolin (a protein matrix), arranged in concentric layers.
The duration of this process varies considerably depending on factors such as the species of mollusk, environmental conditions (water temperature, salinity, nutrient availability), and the specific cultivation methods employed (if applicable). Natural pearl formation, occurring without human intervention, can take years, potentially spanning from months to several years for a pearl to develop to a marketable size. The quality and value of a pearl are influenced by the thickness and consistency of the nacre layers.