Mother of Pearl is the name for the iridescent layers of
nacre (naker) which is the natural mineral substance
secreted by the mantle tissue of the mollusk. Nacre is
continuously deposited on the inner surface of the shell
to smooth it. Nacre is a defense against parasites and
debris. It is the sole component of rare natural pearls.
Nacre is the layered coating on the shell bead in
cultured pearls.
