Sea shells in the context of "Mactra corallina"

Mineralized tissues are biological tissues that incorporate minerals into soft matrices. Typically these tissues form a protective shield or structural support. Bone, mollusc shells, deep sea sponge Euplectella species, radiolarians, diatoms, antler bone, tendon, cartilage, tooth enamel and dentin are some examples of mineralized tissues.

These tissues have been finely tuned to enhance their mechanical capabilities over millions of years of evolution. Thus, mineralized tissues have been the subject of many studies since there is a lot to learn from nature as seen from the growing field of biomimetics. The remarkable structural organization and engineering properties makes these tissues desirable candidates for duplication by artificial means. Mineralized tissues inspire miniaturization, adaptability and multifunctionality. While natural materials are made up of a limited number of components, a larger variety of material chemistries can be used to simulate the same properties in engineering applications. However, the success of biomimetics lies in fully grasping the performance and mechanics of these biological hard tissues before swapping the natural components with artificial materials for engineering design.

Shell money is a medium of exchange similar to coin money and other forms of commodity money, and was once commonly used in many parts of the world. Shell money usually consisted of whole or partial sea shells, often worked into beads or otherwise shaped. The use of shells in trade began as direct commodity exchange, the shells having use-value as body ornamentation. The distinction between beads as commodities and beads as money has been the subject of debate among economic anthropologists.

Shell money has appeared in the Americas, Asia, Africa and Australia. The shell most widely used worldwide as currency was the shell of Cypraea moneta, the money cowry. This species is most abundant in the Indian Ocean, and was collected in the Maldive Islands, in Sri Lanka, along the Malabar coast, in Borneo and on other East Indian islands, and in various parts of the African coast from Ras Hafun to Mozambique. Cowry shell money was an important part of the trade networks of Africa, South Asia, and East Asia.