[Crystallography of 804 renal calculi]

We analyse a total of 804 kidney stones in 225 patients aged between 10 and 71 years, with an average age of around 45, by means of the following techniques: optico-differential analysis (immersion method, PRIEN and FRONDEL, 1947), fine plate, X-ray diffraction, infrared-ray spectroscopy and qualitative chemical analysis. In all the stones, we identify the composition of the nucleus and periphery separately. Our results give 51.32% of patients forming essentially oxalic stones, 28.31% uric ones, 19.46% phosphatic and 0.44% cystine stones. These statistics coincide quite closely with those obtained by Cifuentes (quot. in Dalet, F.; Pinto, B., 1976) in Madrid and differ a little more from those obtained by the Puigvert Foundation (quot. in Dalet, F.; Pinto, B., 1976) in Barcelona. They are also similar to those obtained by Sutor (1974) for non Anglo-Saxon, industrialized countries, such as Czechoslovakia and Kuwait. We identify the following components in this collection of stones: anhydrous uric acid, dihydrate uric acid, amorphous urates (sodic, ammonic), whewellite, wedellite, hydroxyapatite, carbo-apatite, struvite, newberyte, whitlockite, brushite and cystine. We found no xanthine stone.