Mineralogical and radioactive properties of some Egyptian granitoid rocks and their suitability for ornamental stones

الملخص EN

Granitoid rocks are widely distributed all over the Egyptian Shield, constituting approximately 60 % of its plutonic assemblage.

Granitoid ornamental stones could be commercially defined as a visibly granular, igneous rocks ranging in color from pink to light or dark grey.

Detailed mineralogical composition was investigated by using polarizing microscope (Olympus BX50, Japan) and X-ray diffraction (XRD) X-ray model X’ Pert ProPhillips MPD PW 3050 / 60 X-ray diffractometer.

Radiometric measurement is recommended before utilizing the decoration stones which could be used in different purposes of construction especially indoor purposes.

Twelve selected representative samples from some Egyptian granitoids rocks were examined by using Inductive coupled plasma Mass Spectrometer (ICPMS) in Acme analytical labs, Canada.

The measured values were in ppm and would be transformed to Bq / kg which normally used to measure it in construction or building materials.

Based on radiation measurement of (U and Th) for the studied granitoids of Gabal Shawab and Gabal Abu Shieh El-Atshan granites lie within the world-wide safety limits of constructing building materials, while Gabal El-Sibai and Gabal Homrit El-Gergab granites not realize these safety requirements.

Homrit El-Gergab granitoids represented the highest concentration of the studied granitoids while Gabal Shawab represented the lowest one.

Ornamental stones of G.Shawab and Wadi Abu Shieh El-Atshan are suitable for all construction weather indoor or outdoor decoration purposes.