Periodic Symbol: Ca
Atomic Number: 20
Atomic Weight: 40
Group: Alkaline Earth Metal
Color: Silvery White
Discovered by Sir Humphrey Davy in England, 1808. It originated from the Latin word "calx", which means lime. It was available for large scale until the 20th century.
Calcium is found in limestone, gypsum, and fluorite. Needed in things like teeth, bones, leaves, and shells. It is also useful for setting broken bones.
Parts of bones and cell walls are made from calcium. Calcium is also a important part of blood clotting.
Naturally, calcium does not occur as a metal. It is found in minerals, like limestone. It makes up around 3% of the earth's crust.