Calcium Oxalate Dihydrate Kidney Stone
Calcium oxalate stones are the most common stone type and form when calcium combines with oxalic acid. Oxalic Acic is a waste product that the kidneys remove that contains two carbon atoms, four oxygen atoms, and two hydrogen atoms. A little known fact is that calcium oxalate stones come in two varieties: calcium oxalate monohydrate and calcium oxalate.
Dihydrate stones are softer and more prone to fragmentation by lithotripsy.