Perfection from Disorder
We have discussed in the past the fantastic physical features of shell material. The structural properties of mother-of-pearl, also known as nacre, for instance, a material of great strength and resilience, have been tapped for uses in engineering, optics, electronics, and other hi-tech applications. Not all molluscan shells include a nacreous layer, though. When present, nacre is usually the internal shell layer, showing iridescent, always-shifting colors. (the shells of nau