Calcium strontium or barium, the oxide–nitride coating that results in air is stable and lathe machining and other standard metallurgical techniques are suitable for calcium. In the United States and Canada, calcium is instead produced by reducing lime with aluminium at high temperatures. Calcium provides a link between tectonics, climate, and the carbon cycle. In the simplest terms, uplift of mountains exposes calcium-bearing rocks to chemical weathering and releases Ca into surface water. These ions are transported to the ocean where they react with dissolved CO to form limestone (), which in turn settles to the sea floor where it is
Calcium cycle more calcium, further increasing blood calcium levels . This will continue until the body releases too much calcium into the bloodstream. Excess calcium then promotes the release of calcitonin from the thyroid gland, effectively reversing the process of PTH. Osteoclast activity is stopped and osteblasts take over, utilising the excess calcium in the bloodstream to form new bone. Calcium re-absorption in the kidney is prevented, allowing the excretion of excess calcium through the urine. . Through these hormonal mechanisms, calcium homeostasis is maintained within the body. Calcium is an essential component of soil. When deposited in the form of lime,