Easton's Bible Dictionary

Pearl - (Heb. gabish, Job 28:18; Gr. margarites, Matt. 7:6; 13:46; Rev. 21:21). The pearl oyster is found in the Persian Gulf and the Red Sea. Its shell is the "mother of pearl," which is of great value for ornamental purposes (1 Tim. 2:9; Rev. 17:4). Each shell contains eight or ten pearls of various sizes.