Petoskey stones have a larger, more symmetrical hexagonal pattern than Charlevoix stones. Rock collectors in northern ...

Kidney stones—also known as renal calculi or nephrolithiasis—are hard deposits made of minerals that build up in your urinary tract and form in your kidneys. Sometimes kidney stones can stay ...

What is a kidney stone? Kidney stones, medically defined as renal calculi, are hard deposits that form in the kidneys from chemicals in the urine. “They are literally rocks that are made up of ...