Calcium is never found in its elemental form. Calcium is a silvery, soft metallic element that must be extracted. Through electrolysis it can be drawn from a salt like calcium chloride. This extraction can produce a 98.6 percent pure result. However, 99.5 percent can be achieved through further subliming. Once extracted it forms into a nitrate and oxide.
Following the work of Jons Jakob Berzelius, Sir Humphrey Davy electrolyzed a mixture of lime and mercuric oxide in 1808 successfully isolating calcium for the first time. In 1902, Borchers and Stockem reached 90 percent purity, by using an iron cathode and electrolyzing at 780 degrees F. Today, we obtain calcium by displacing calcium atoms in lime. These are mixed with aluminum atoms in hot low-pressure containers to gather the calcium.
The Earth's crust is comprised of more than 4 percent calcium. This makes calcium the fifth most abundant element in the Earth's crust, and the fifth most dissolved ion in saltwater. Its chemical symbol is Ca and its atomic number is 20. Calcium is found in sedimentary, igneous and metamorphic rocks--mainly in silicate minerals, and dolomite and gypsum.
Calcium covers a full color spectrum depending on its state. Its natural state is silvery to silvery-white and, very rarely, yellowish. Once produced, and exposed to air, it has more of a gray-white look to it. However, calcium salts are colorless. It is not easy to ignite, but when it does, it burns with a high intensity red light.
Although, calcium is calcium, what makes it so unique is its ability to work with other minerals. Calcium carbonate is known for stalagmites and stalactites. It is also found in the skeletons of sponges. Calcium phosphide produces a red smoke that is used by marines to signal each other. Calcium sulfate is used in the ever popular plaster of Paris. Calcium oxide, also known as lime, when mixed with sand creates mortar.
Besides all the chemical advantages and uses that calcium is utilized for, let's not forget what most Americans use it for every day, nutrition. Since nearly 99 percent of the human body's calcium reserves are stored in the bones and teeth, we need to replenish the supply as much as possible. Dairy products are well known for their contributions of calcium to the human body. Some are lactose intolerant and cannot consume large quantities of dairy products. For these people soy milk, oranges and even seaweed can be a great way to get the needed calcium their body needs.