In the development of materials to be used in the production of strong impellers in jet engines, the mother-of-pearl’s structure is imitated. 95% of the mother-of-pearl on the inner layer of many shellfish’s shells is chalk, but mother-of-pearl is 3,000 times stronger than chalk thanks to its composite structure. When this structure is examined, it is seen that microscopic tablets, only eight microns (1 micron=10–6 meters) in width and one half of a micron in depth, are arranged as layers.