Eloquence of the Sardine by Bill François

 

"Even on the outside, the oyster shell is a material unlike any other. The mother-of-pearl, or nacre, from which it's made is a biomineral, a mineral produced by a living being. This alliance between the animal and mineral kingdoms gives it extraordinary properties. Mother-of-pearl is composed of 99 percent calcium carbonate, also known as chalk. But the oyster knows the secret art of transforming soft and crumbly chalk into rough and precious mother-of-pearl."