Calcium is a very ductile silvery metal (sometimes described as pale yellow) whose properties are very similar to the heavier … See more

Calcium compounds were known for millennia, though their chemical makeup was not understood until the 17th century. Lime as a building material and as plaster for statues was used as far back as around 7000 BC. T… See more

At 3%, calcium is the fifth most abundant element in the Earth's crust, and the third most abundant metal behind aluminium and iron. It is also the fourth most abundant element in the lunar highlands. Sedimentary calcium car… See more