This element is similar in its physical and chemical properties to those of its heavier peers in the alkali metal group: strontium and barium. Calcium is the fifth most abundant chemical element in the Earth’s crust, and the third metal in terms of arrangement after aluminum and iron.
It is often found there in the form of calcium carbonate compound which goes into the composition of limestone. It is also found in the form of other compounds in the gypsum, anhydrite, fluorite and apatite minerals, which are also natural raw materials for calcium.