The term 'shell of bivalve' can be summarized as the hard outer covering of a bivalve mollusk, such as an OYSTER. Oysters are a type of mollusk that have two shells connected by a hinge, and the shell of a bivalve is the hard outer covering that protects the mollusk from predators and other environmental factors. Oysters are a popular seafood delicacy, and their shells are often used for decoration or jewelry.