Abstract
Infrared absorption spectra for 66 mechanical mixtures of quartz, orthoclase and oligoclase are obtained with an infrared spectrophotometer using KBr in the wavelength region from 11 to 25 microns. The intensities of absorption bands at 12.65 and 11.00 microns are compared for quartz and at 16.00 and 15.60 microns for orthoclase and oligoclase respectively. Calibration curves for the quartz content and for the orthoclase and oligoclase contents are shown. A technique is suggested for the semiquantitative determination of these minerals in acidic rocks.
