40. Qualitative methods (such as the Oxford Stone Analysis Kit) or urolith analysis do not provide reliable information about the mineral composition of uroliths. They should only be used as a tentative index of urolith composition, and only then if subsequently validated by quantitative methods of urolith analysis. Additional information may be obtained at our Web site: www.cvm.umn.edu. Click the link to department and centers to find Minnesota Urolith Center.