Shell pendant or garland model 2021 from "Cebu / Philippines"

 The shell (or in the case of snails also the 'snail shell') is an (usually) external skeleton consisting of lime (calcite and / or aragonite) and other minerals, which is produced by a mollusk (tribe of Mollusca). The shell provides the animal with firmness and protects the animal against external influences such as predation, injury, dehydration, etc. The shell grows with the mollusk during life. The science that studies all aspects of mollusks is called malacology. A branch of malacology that deals only with the shell is called conchology. In the past it was wrongly believed that malacology was not concerned with the shell and the distinction between malacology and conchology was made very sharp by some. In current practice, the terms are often interchangeable and more or less considered synonymous. Shells can be used to pave a walkway, which is sometimes called a 'shell path'. Shells can also be burned into shell lime, which was often used as a building material in the past instead of cement.