mother-of-pearl
The hard, silvery, brilliant, internal layer of several kinds of shells, particularly oysters, which is often variegated with changing purple and azure colors; nacre. (Webster, 1882)
Ma put the tickets inside her mother-of-pearl pocketbook and carefully snapped shut its little steel clasps. – By the Shores of Silver Lake, Chapter 3, "Riding in the Cars"
Mother-of-pearl is the common name for nacre,the hard, silvery, iridescent coating of minerals secreted by oysters, abalone, and other mollusks, and can be found in both ocean and fresh water
mollusks. It coats the inside of the mollusk's shells in order to keep parasites and other foreign objects from harming their bodies. Mother-of-pearl is the same substance that forms a pearl when deposited onto a grain of sand or other object that enters - or is placed - inside the animal's shell. Laura Ingalls' engagement ring had a center garnet, flanked by pearls, highly valued as gemstones.
Mother-of-pearl is made of primarily two substances: aragonite, a natural protein crystal containing calcium carbonate, and elastic biopolymers which increase its strength and durability. Mother-of-pearl appears iridescent because tiny grooves in the plates of aragonite reflects different colors of visible light when viewed from different angles.
The shells producing mother-of-pearl can be cut or carved into shape, or tiny bits of the nacre can be lacquered together to form larger sheets. Although mother-of-pearl may naturally occur in many colors, it can be bleached or dyed as desired. At the time of the "Little House"® books, mother-of-pearl could be found in cutlery, buttons, brushes and combs, inlay on furniture, or on the actual shells that were displayed for their beauty. Perhaps some of the sea shells on the whatnot in the James Wilder home (see Farmer Boy) were chosen for their beautiful, pearly insides.
