Explanation:

Calcium oxalate

A kidney stone or renal calculus is also known as nephrolith is a solid material formed in the kidneys from the minerals found in the urine. While most of the cases of kidney stones, this is caused due to genetic reasons , environmental factors or a combination of the two, factors such as obesity intake of certain foods, medications and lack of water intake also attribute to the formation of kidney stones. The major chemical compound found in human kidney stones is calcium oxalate or oxalate of lime. With the chemical formula CaC2O4 or Ca (COO)2, this is also found in beer stone, as scaling in the containers in breweries.