Mother of Pearl is similar to pearls in chemical composition, but unlike a pearl, which is the result of nacre secretions emitted to protect the mollusk from a foreign irritant entering the shell, Mother of Pearl comes from the actual shell of the animal.
Although far more abundant, and therefor, far less valuable than pearls, Mother of Pearl has been a major component in jewelry and decorative arts for thousands of years. From ancient Egypt and Persia, to ancient China, Mother of Pearl has been a prized semi-precious gemstone throughout human history. From the early 1900s, the coastal region of Broome, in Western Australia has been one of the largest producers of mother-of-pearl, accounting for up to 80% of world supply.
As part of the shell building process, the mollusk will deposit layers of calcium carbonate held together by an organic horn-like compound called conchiolin. This combination of calcium carbonate and conchiolin is called nacre or mother-of-pearl.
Mother of Pearl & Red Coral Brooch by Michael Zobel (left)
Mother of pearl (nacre) is a naturally-occurring organic-inorganic composite. The nacre is secreted by epithelial cells in the mantle tissue of certain mollusk species such as Abalone. In these mollusks, nacre is continually deposited onto the inner surface of the animal's shell. This process creates the iridescent nacreous layer, commonly known as mother of pearl.
The iridescent quality of nacre (or mother-of-pearl) is due to the fact that the thickness of the aragonite platelets are about 0.5 micrometres, which is comparable to the wavelength of visible light. This results in absorptive and reflective effects on different wavelengths of light (pseudochromatic coloration), resulting in different colors of light being reflected when observed at different viewing angles.
Chemical composition: CaCO3
Semi-Precious Stones