The determination of the anorthite content of plagioclases by the application of the standart deviation method to the oc-ray diffraction analyses
ABSTRACT: The determination of the anortMt© contents of plagioclaieg by x*ray diffractton analyses is anextensively used method`. In order to control the results obtained during these analyses, the method known as"standart deviation" Indicating the rate of error in readings amd showing the degree of precisene§s of theprocedure to progress, may be utilized, TMs metbod here, is applied to a rock sample analysed» by a Philipsdiffractometer using (OuKa j) radiation, for the purpose of employing the graphical values of its (181) and(131- ) reflectMtm, and in this way the anortMte content of the plagioclascs is dctcriiiinctl