0 a smooth, hard substance forming a layer inside the shells of some sea creatures. It is white but also seems to shine with different colours, and is used to make buttons and for decoration.
The oblique aperture is rounded-oval, with a very thin layer of bluish iridescent nacre within.
The mussel's nacre is typically white or bluish, and the shell in general is rounded and generally symmetrical over the axis.
Most molluscs with shells can produce pearls, but only the pearls of bivalves and some gastropods, whose shells are lined with nacre, are valuable.
For example, the organic component in nacre is known to restrict the growth of aragonite.
Multilayer stacks (laminates) have a structure similar to nacre, which provides mechanical strength at water free conditions.
The acute outer lip is narrowly margined, iridescent within, the nacre smooth, but apparently lirate.
Some are fine examples of inlay work with nacre and ivory.
The colour is yellowish chalky white over brilliant nacre.
