Calcium oxalate (CaC2O4 or Ca (COO)2) imaged using a SEM (scanning electron micrograph)
This image came from a kidney stone. Kidney stone crystals are formed by the precipitation of calcium oxalate in urine. The resulting hard, round stones, which are also known as calculi, may cause severe pain, especially as they pass down the urinary tract. Large stones may need to be surgically removed or broken down using ultrasound therapy.
However, calcium oxalate may also be used in the manufacture of ceramic glazes.