Quantitative analysis of minerals by x-ray powder diffraction

Grain size, instrumental variations and preferred orientation are the three primary sources of experimental error for quantitative X-ray diffraction analysis and must therefore be controlled before any attempt can be made to quantify sample mineralogy. Previous equations have neglected the surface layer effect yet, this effect may account for as much as 50% of the observed intensity. In samples which contain absorbers, the effect is even more pronounced. Computer solutions of intensity equations have verified the surface effect relationship and allow for determination of weight percentage compositions for multi-component mineral systems with an accuracy of 3.5%. Standard curves are not needed.