The relationship between mechanical properties and crossed-lamellar structure of mollusk shells

Composites produced in nature, such as mollusk shells, bones, etc., are renowned for their unique structures and excellent properties. In this paper the microstructure and mechanical properties of the shell of Conus betulina Linnaeus are investigated. The results indicate that the mechanical properties of the shell are anisotropic. After removal of the organic protein in the shell, the three-point bending strength significantly decreases, to about 1/20th or 1/30th of the original value. The organic matrix plays an important role in the hierarchical structure of the conch shells, as it promotes load transfer between adjacent aragonite layers.