Cement is the foundation of our civilization — quite literally. We couldn’t construct the buildings around us without cement.

All are made largely of aragonite, the original shell material. The recent shells retain the organic material that give the shells their color and nacreous sheen. Nacre (mother of pearl) is an ...

It contains microscopic hexagonal “tablets” made of aragonite (one of the most common, naturally occurring forms of calcium carbonate) held together by soft biopolymer, kind of like an organic ...