Pearl or parasite enters a bivalve mollusk and settles inside the shell. The mollusk, irritated by the intruder, forms a pearl sac of external mantle tissue cells and secretes the calcium carbonate and conchiolin to cover the irritant. This secretion process is repeated many times, thus producing a pearl. Natural pearls come in many shapes, with perfectly round ones being comparatively rare. Typically, the build-up of a natural pearl consists of a brown central zone formed by columnar calcium carbonate (usually calcite, sometimes columnar aragonite) and a yellowish to white outer zone consisting of nacre (tabular aragonite). In a pearl cross-section
Pearl (given name) the United States in the 1990 census. Authors Pamela Redmond Satran and Linda Rosenkrantz noted in their 2007 book "The Baby Name Bible" that Pearl is in fashion again with hipster parents in the United States. Pearl can also be a surname, one which is common among Jews. Zane Grey, the male American writer of Westerns, was born Pearl Zane Grey. Pearl Buck was a well-known female American author. Minnie Pearl was a country and western comedian and singer. The Poor Pitiful Pearl doll was a vintage doll manufactured by the Brookglad Corp., Gladtoy Company and later by the Horsman