Combined x-ray diffraction and microchemical gallstone analysis in determining the sequential events in biliary lithogenesis

Seventy-five gallstones were analyzed layer by layer by x-ray diffraction and microchemical techniques. Microchemical analysis showed that protein was present in 96% of stone nuclei. Application of x-ray diffraction analysis to biliary calculi revealed that cholesterol in three crystalline polymorphs and the three forms of calcium carbonate were the predominant crystalline components. "Cholesterol" and "mixed calculi" revealed differences in their composition. The value of the application of multiphasic qualitative analytical techniques to gallstones is discussed and the pattern of the probable sequence of events in the formation of "mixed" gallstones indicated. It appears that in this process of biliary lithogenesis epitaxy may play a significant role especially in the growth of calculi after formation of the nidus.