Method and reliability of crystallographic stone analysis.

The methods of daily routine analysis of urinary stones in one laboratory, employing a combination of microscopy, spectroscopy, chemistry, and X-ray diffractometry, are described. A methodologic study indicates that these methods are complementary and no one method is sufficient. Quantitative estimates are in general best obtained by X-ray diffraction, whereas qualitative identification of depositional sequence and the quantitative determination of minor constituents must depend on microscopic and chemical methods. Components at a concentration of 1 per cent may be identified whereas those in excess of 5 per cent are rarely overlooked. Concentrations are correct within +/- 10 per cent of stone mass.