calciaum as the element is a grey silvery metal. calcium's a chemical symbol is "Ca",atomic number 20 and the 5th most abundant element in the earth's crust. It is a chemical element which is essential for living organisms, including humans. Calcium is a mineral found in many foods. The body need calcium to maintain strong bones and to carry out important functions. Almost all calcium is stored in bones and teeth,where it supports their structure and hardness.