Calcium is extremely important for living organisms. It is a prime material in helping mineralize bones and shells. As a result calcium is the most abundant metal by mass in many animals. Approximately ninety-nine percent of the human body’s calcium is found in the bones and teeth. Calcium cannot be found naturally in its elemental state, but does appear commonly among certain sedimentary rocks and minerals such as calcite, dolomite, and gypsum. It is also found in igneous and metamorphic rocks. Overall calcium is the 5th most abundant element by mass in both the Earth’s crust and dissolved seawater.
Calcium (in latin calcis meaning “lime”) was used by the Romans in the first century to prepare lime as calcium oxide. Plasters containing calcium have been known to help set broken bones since 975 AD. It was isolated in 1808 in England by Sir Humphry Davy, by using an electrolyzed mixture of lime and mercuric oxide. It was not available on a larger scale until the early 20th century.
