Kidney stones are small, hard deposits of minerals and various salts, usually yellow or brown. They are different in size: some as small as grains of sand, others as large as pearls. Stones vary in chemical composition. Basically, calcium, urate, struvite, and cystine are detected. However, in some people, different types of stones can occur simultaneously. If a person begins to produce less urine or in the urine, the concentration of calcium,...