Which of the following technique is used to detect the substance present in the gall bladder stones or the kidney stones?

X-ray diffraction method is used in the analysis of urinary calculi for fast and reliable results. It even enables to determine the propotional rate of the paicular crystalline components forming the calculus. It is also used for the detection of gallstones of all types of composition such as calcium stearate, calcium bilirubinate, cholesterol, calcite or dioxycholic acid. Ref: World of Nanobioengineering: Potential Big Ideas for the Future By Amin Elsersawi, Pages 46, 48