The Abu Rushied area, situated in the South Eastern Desert of Egypt is a distinctive occurrence of economically important rare-metal mineralization where the host rocks are represented by granitic gneisses. Correspondingly, mineralogical and geochemical investigation of pegmatites pockets scattered within Abu Rusheid granitic gneisses revealed the presence of Hf-zircon, ferrocolumbite and uranyl silicate minerals (uranophane and kasolite). Electron microprobe analyses revealed the presence of Nb-Ta multioxide minerals (ishikawaite, uranopyrochlore, and fergusonite), uraninite, thorite and cassiterite as numerous inclusions in the recorded Hf-zircon and ferrocolumbite minerals. Abu Rusheid pegmatites are found as small and large bodies that occur as simple and complex (zoned) pegmatites. Abu Rusheid rare-metal pegmatites occur as steeply dipping bodies of variable size, ranging from 1 to 5 m in width and 10 to 50 m in length. The zoned pegmatites are composed of wall zone of coarser granitic gneisses, intermediated zone of K-feldspar and pocket of mica (muscovite and biotite), and core of quartz and pocket of mica with lenses of rare metals. The zircon is of bipyramidal to typical octahedral form and short prisms. Because the zircon of the investigated Abu Rushied pegmatite frequently contains hafnium in amounts ranging between 2.31 and 11.11%, the studied zircon was designated as Hf-rich zircon. This zircon commonly exhibits a normal zoning with rims consistently higher in Hf than cores. The bright areas in the crystal either in core or rim showed a remarkable enrichment in hafnium content (8.83-11.11%) with respect to the dark zones (3.19%). The investigated ferroclumbite commonly exhibits zoning; the dark zone is low in the Ta and U but the light zone is enriched in Ta (13%) and U (1%). EMPA analyses indicate the chemical composition of ishikawaite with U ranging from 0.68 to 0.79 per formula unit. Uranopyrochlore species has dominant uranium in the A-site where it ranges from 12.72 to 16.49% with an average of 14.84%. The calculated formula of the studied fergusonite is A (Y 0.303 ∑REE 0.014 U 0.135 Th 0.063 Ca 0.013 Pb 0.006 Si 0.213 Zr 0.035 Hf 0.048 Fe 0.105)∑ 0.935 B (Nb 0.61 Ta 0.084 Ti 0.01)∑ 0.704 O 4. The presence of uraninite (high Th, and REE contents) and thorite, indicates that these minerals magmatic processes and followed by hydrothermal processes which are responsible for the precipitation of Nb-Ta multioxide minerals. Uranophane and kasolite of Abu Rusheid pegmatites are most probably originated from hydrothermal alterations of the primary uraninite. Abu Rushied pegmatites are characterized by being of ZNF-type due to their marked enrichement in Zr, Nb, and F, with a typical geochemical signature: Zr, Nb >>Ta, LREE, Th, P, F. Accordingly, the mineralized Abu Rushied pegmatite can be considered as a promising target ore for its rare metal mineralization that includes mainly Nb, Ta, Y, U, and REE together with Zr, Hf, Sn and Th.

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An economically important rare -metal mineralization is recorded in the pegmatite bodies of Gabal Ras Baroud younger granitic pluton, Central Eastern Desert of Egypt. These pegmatite bodies are of variable size and are compositionally zoned. Radiometric measurements of some anomalous pegmatite samples show that their equivalent uranium (eU) content is 219 -328 ppm, whereas their equivalent thorium (eTh) content is 783 -1101 ppm. On the other hand, the analysis of several separated mineral grains of some pegmatite samples using a scanning electron microscope and X -ray diffraction revealed the presence of several economic minerals. These minerals include zircon, thorite, phlogopite mica, and columbite, in addition to the samarskite -Y mineral. Thorite was found as numerous inclusions of variable size and pattern in zircon. Electron microprobe analysis confirmed the presence of samarskite -Y whose composition corresponds to the empirical formula [(Y 0.49

Fergusonite-Y occurs at the mineralized pegmatite injected in Abu Dob granitic pluton, Central Eastern Desert of Egypt as dark brown, anhedral clusters of distinguishable megascopic crystals up to tens of millimeters. The mineral is intimately intergrown with Hf-Zircon. Heavy minerals mineralogy for the studied samples revealed that both fergusonite-Y and Hf-Zircon could reach 28% by weight of the original rock sample. Beside these minerals, some kasolite, titanite and allanite-Ce minerals occur in much lower amount. Allanite-Ce was found as numerous inclusions of variable size and pattern in titanite. Detailed microscopic examination, X-ray diffraction (XRD) and Environmental Scanning Electron Microscope (ESEM) were used to identify and describe the studied minerals. Physical upgrading of these minerals was carried out using gravitative and magnetic separation techniques. Gravitative separation proved rather good potentialities to attain a good concentrate of both fergusonite-Y and Hf-Zircon with an acceptable recovery. By applying the laboratory Carpco high intensity lift-type magnetic separator for the tabling concentrates, it was possible to attain a good separation between fergusonite-Y as magnetic concentrate and Hf-Zircon as non-magnetic concentrate. Due to the economic importance of the studied minerals and their metal values as they are used in several industrial applications, it is recommended to subject both of the final concentrates to proper hydrometallurgical treatment to extract their metal content.

The Hangaliya gold deposit, located in the South Eastern Desert of Egypt, comprises a series of milky quartz veins along NW-trending Hangaliya shear zone, cutting through granitic rocks of Gabal Nugrus monzogranite. This shear zone, along with a system of discrete shear and fault zones, formed in the late deformation history of the area. The quartz vein emplacement took place under a brittle-ductile shear regime. Auriferous quartz veins are slightly sheared and boudinaged within the shear zone, especially in the hematized granite. Hydrothermal alteration is pervasive in the granitic wall rocks including sericitization, chloritization, fluoritization, sulphidization and minor carbonatization. The altered zones and associating quartz veins contain sulphides, gold, silver, cobalt, bismuth, and uraninite minerals.The Hangaliya gold veins include gold, silver, cobaltite, native bismuth, chalcopyrite, pyrite, galena, ferrocolumbite, fergusonite and uraninite. The Au-ore occurs in the quartz veins and adjacent wall rocks as dissemination in chalcopyrite and pyrite. Presence of refractory native silver, bismuth and cobalt in chalcopyrite is inferred from microprobe analyses. Wall rock sulphidization also likely contributed to destabilising the gold-silver, cobalt, bismuth assemblages and precipitation of the minerals in the hydrothermal alteration zone adjacent to the quartz veins. Gold occurs in two main modes: "invisible gold" in sulphides and native gold. Most of the "invisible gold" occurs in chalcopyrite and bismuth. The altered granites in the Hangaliya shear zone are enriched in Au, Ag, Bi, Co, and Ni with chalcopyrite, which suggests derivation of these metals from serpentinites due to interaction with the felsic Nugrus granite.