• Calcium Oxalate is the most common type of stone.  It’s found in 70 percent of cases.  These stones vary in shape and size. 
  • Uric Acid is found in about ten percent of all cases.  A high amount of uric acid in the urine can lead to these types of stones.  Those who have gout are at an increased risk for this type of stone and they are hard to identify on standard x-rays. 
  • Struvite is found in about nine percent of all stones.  They are made of magnesium and ammonium phosphate.  Infections in the urinary system can cause this type of stone.
  • Calcium Phosphate makes up about nine percent of stones. 
  • Cystine can be found in two percent of all stones, which is a by-product of the amino acid, cysteine.  People who form these stones have a genetic trait that causes a high cysteine level in the urine.  They look like brown sugar. (Source:www.uwhealth.org/healthfacts)