Oyster Shells: Composition, Structure, And Significance For Marine Ecosystems

Oyster shells are composed primarily of calcium carbonate (CaCO3), which is the main component of most marine mollusk shells. The presence of calcium carbonate gives oyster shells their characteristic hardness and strength. The inner layer of the shell, known as the nacre or mother-of-pearl, is composed of aragonite, a more resilient form of calcium carbonate. The shell is also composed of a protein called conchiolin, which helps to bind the calcium carbonate crystals together.