A nondestructive physical method used for chemical analyses of solids and liquids. The specimen is irradiated by an intense X-ray beam and the lines in the spectrum of the resulting X-ray fluorescence are diffracted at various angles by a crystal with known lattice spacing; the elements in the specimen are identified by the wavelengths of their spectral lines, and their concentrations are determined by the intensities of these lines. Constituent elements are identified based on the unique wavelengths of fluorescent X-rays they emit and concentrations are estimated on the intensity of the released X-rays. It can be used on pottery, obsidian, glass, and some metal and under most circumstances is totally non-destructive. In general terms the method is more suitable for the analysis of the major elements in a specimen, though trace elements can be determined in some cases. Since automation of recording and sample changing is possible, large numbers of samples can be analyzed at speed, which gives this method a definite advantage over atomic absorption spectrometry and optical emission spectrometry.