Calcium was first isolated as a pure metal by Sir Humphry Davy, in 1808, after he learned that Jöns Jacob Berzelius and Magnus Pontin had prepared an amalgam of calcium and mercury. Calcium is the main constituent of lime, which was used as early as the seventh millennia B.C. to plaster walls and make statues and pottery.
Calcium is a highly reactive element that is only found in combination with other elements in nature. Lime was prepared as calcium oxide by the Romans in the first century, while plaster of Paris was prepared as calcium sulfate in the 10th century. Sir Humphry Davy isolated elemental calcium by electrolyzing a mixture of calcium oxide and red oxide of mercury to form a calcium-mercury amalgam that he then distilled to remove the mercury. He named it calcium from the Latin word "calcis," meaning lime.
Calcium was not produced in large quantities until the 20th century, when its uses were broadly developed. In modern times, calcium compounds are widely used in industry as a reducing agent to isolate other elements, as an alloying agent in the production of alloys of other metals, and in the preparation of cement and mortar for use in construction. It is also widely used in food production and is a mineral necessary for life.