Iridescent pieces of shell from the abalone sea mollusk.
Abalone refers both to the nacre (mother of pearl) and the marine snails that produce it in their shells.
Nacre is made of a aragonite bound together with organic matter – biopolymers similar to the proteins found in silk.
The nacre found in abalone shells can vary in color from the more common mother of pearl colors of silvery white, to bands of deep green, purple, and blue. These striking colors are why it is used to make jewelry.