THE shells of molluscs are remarkably strong even though they are composed
mainly of the brittle mineral aragonite. Now a study of the giant pink queen
conch (Strombus gigas) has revealed the intricate structure that is the
secret to their strength.
Arthur Heuer of Case Western Reserve University in Cleveland, Ohio, found
that in conch shells, layers of tiny platelets are arranged at right angles to
each other and held together by a protein 鈥済lue鈥� (Nature, vol 405, p
1036). The platelets dissipate stress into numerous tiny cracks instead of one.
This arrangement makes shells over a thousand times tougher than pure aragonite
crystals. 鈥淭his could be the inspiration for new lightweight and tough ceramic
composites,鈥� Heuer says.