Abstract:
The main objectives of this study were to know natural minerals contents to classify their types
and determine corundum type. Energy Dispersive X-ray Fluorescence spectrometry, X-ray
diffraction and Energy Dispersive X-ray Spectrometry coupling with Scanning Electron
Microscope have been utilized to determine the mineralogical and elemental composition of semi
gemstone samples collected from two different mine locations in Darfur region western Sudan.
Results obtained from spectroscopic analyses indicated that Aluminum Oxide (Al2O3) was
predominated in FDY sample(A) and Silica (SiO2) was main contain in ODS sample(B) as well
as different percentages of some metal oxides including trace and rare earth elements. According
to the outcome of the Energy Dispersive X-ray Fluorescence results the FDY sample is
characterized as Corundum (Ruby) and while the ODS sample is classified as Quartz
(Carnelian). These characterizations are depended on physical appearance and color that when
compared to the previous data of gemstones in addition to the analyzing results .The analysis
showed that ruby major revealed composition were Al2O3 (79.02 %); SiO2 (10.88%);
SO3(4.96%) Fe2O3 (2.27%); CaO (1.06%); TiO2(1.08%) and quartz majority compositions were
SiO2 (94.23%) ; Al2O3 (1.96%); SO3 (0.66%) Fe2O3 (2.10%); CaO (1.05%); TiO2 (0.03%). X-ray
Diffraction scanning tests of the samples showed that a vast majority represented by
corundum (93.3%)and quartz (99.1%) in FDY and ODS samples respectively as dominant
compound ,similarly for more investigation and delicacy Energy Dispersive X-ray Spectrometry
coupling with Scanning Electron Microscope scan analyzing indicated that Al
compounds(Al2O3) were outnumbered Si compound(SiO2) in FDY sample while in ODS
sample there was a significant presence of Si contents represented by standard level (SiO2) on
the bases of available facts of the study FDY sample considered to be corundum (ruby) and
ODS sample as quartz origin.
