20Ca Calcium

Year Discovered


Discovered By

Sir Humphry Davy of England

Biological Rating

Necessary for all life.


Named from the Latin word meaning “lime,” calcium is a fairly soft, silvery-white metal. It is very abundant in the Earth’s crust, being the fifth most abundant element. It is reactive in the presence of oxygen and water, although not as reactive as magnesium. Calcium is used in alloys with other metals and in purifying zirconium, thorium, uranium and several of the rare-earth metals. It can purify molten metals by removing carbon, sulfur and oxygen from the metals. Calcium with oxygen forms lime, which is used extensively. It can be converted into quicklime, which is a cheap industrial base, and is used in water treatment and many building materials, such as cement, wall board, plaster and plaster of Paris.

Biological Benefits

Calcium is essential to life. It is one of the six bulk elements, being the 5th most common element in the human body. It is a structural material, being present in cell walls, bones, teeth, shells and leaves. It has a role in regulating the heartbeat and in blood clotting.

Role in Life Processes

Essential to life processes in plants and animals.

Percentage Amount in the Human Body: 1.43%


Many minerals contain calcium. Calcium minerals are very common and can be mined anywhere. It is chiefly obtained from limestone, dolomite and gypsum. Common calcium-bearing minerals include anhydrite (calcium sulfate), gypsum (hydrated calcium sulfate), and aragonite or calcite (calcium carbonate).