Margarites giganteus , common name the marine margarite , is a species of sea snail , a giant gastropod mollusk in the family Margaritidae . Margarites giganteus , common name of the marine margarite , is a species of sea snail , a huge gastropod mollusk in the Margaritidae family . Margarites giganteus , common name of the giant margarite , is a species of sea snail , a marine gastropod mollusk in the Margaritidae family .