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Three volcanic dykes, rhyolite, dacite and trachyandesite cutting a radioactive granite, located between Latitudes 22 degrees 47' 396 ''-22 degrees 47' 884 '' N and Longitudes 31 degrees 54' 883 ''-31 degrees 54' 894 '' E in the south Western Desert of Egypt were sampled and analyzed by X-ray diffraction, Fe-57 Mossbauer spectroscopy and chemical method. They are consisted of feldspar and quartz together with some paramagnetic minerals including aegirine plus minor riebeckite in the rhyolite; aegirine plus some riebeckite in the dacite; and riebeckite plus trace aegirine in the trachyandesite, respectively. The bulk content of iron in each dyke has characteristic ferric-quadrupole splitting and oxidation values: 0.29 millimeters per second (mm/s) and 100% for rhyolite; 0.31 mm/s and 82% for dacite; and 0.35 mm/s and 0.69% for trachyandesite. Variations in the quadrupole splitting have been attributed to changes from the local crystal chemistry, while the oxidation variations are source-related.