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Mother of pearl business card box #1529
The Country of Origin : Rep.of Korea
Size (mm) : 110(w) x 75(l) x 45(h)
Size (inch) : 4.3(w) x 3.0(l) x 1.8(h)
What is Mother of Pearl ( =Nacre ) ?
Nacre is composed of hexagonal platelets of aragonite (a form of calcium carbonate) 10-20 m wide and 0.5 m thick, arranged in a continuous parallel lamina. These layers are separated by sheets of organic matrix composed of elastic biopolymers (such as chitin, lustrin and silk-like proteins). This mixture of brittle platelets and the thin layers of elastic biopolymers makes the material strong and resilient, with a Young's modulus of 70 GPa. Strength and resilience are also likely to be due to adhesion by the "brickwork" arrangement of the platelets, which inhibits transverse crack propagation. This design at multiple length sizes increases its toughness enormously, making it almost equivalent to that of silicon.
Nacre appears iridescent because the thickness of the aragonite platelets is close to the wavelength of visible light. This results in constructive and destructive interference of different wavelengths of light, resulting in different colors of light being reflected at different viewing angles.
Nacre is secreted by the epithelial cells of the mantle tissue of some species of mollusk. The nacre is continuously deposited onto the inner surface of the shell, the iridescent nacreous layer, commonly known as mother of pearl. The layers of nacre smooth the shell surface and help defend the soft tissues against parasites and damaging debris by entombing them in successive layers of nacre, forming either a blister pearl attached to the interior of the shell, or a free pearl within the mantle tissues. The process is called is encystation and it continues as long as the mollusk lives.
Chief sources of mother of pearl are the pearl oyster, freshwater pearl mussels, and abalone. Also widely used for pearl buttons, especially during the 1900s, is the shell of the great green turban snail Turbo marmoratus.
