Alekseev and one co-author reported in late 2023 on the accessory wodginite and on the discovery of titanium-bearing wodginite and Fe and Ti-bearing wodginite in lithium-fluorine granites from the Abu Dabbab and Nuweibi massifs in Eastern Egypt. The wodginite group's mineral association includes tantalum-bearing cassiterite and tin-bearing tantalum-niobate minerals: tantalite-(Mn), columbite-(Mn), and microlite.
Three forms of wodginite crystallization were identified:
- Rims around columbite-(Mn) and tantalite-(Mn) varying from 1.5 to 21.9 µm in thickness,
- Micro-inclusions in cassiterite ranging from 5.4 to 27.0 µm in size, and
- Autonomous crystals measuring 3-124 µm in length.
Wodginite in the Nuweibi massif is mainly found in porphyritic granite of late-stage porphyry intrusion. It has a similar composition to the worldwide wodginite of rare-metal granites, but exhibits a lower content of TiO2 (average 0.54%) and is a mineral indicator of rich tantalum ore deposits. In contrast, wodginite in the Abu Dabbab massif is replaced by titanium-bearing wodginite (Ti/(Sn + B Ta + Ti + Fe3+) = 0.23) and is associated with Fe and Ti-bearing wodginite. Wodginite and Ti-bearing wodginite are maximally enriched in manganese (Mn/(Mn + Fe2+ +Ca) = 0.95), expressed in all intrusive phases of the massif, and are mineral indicators of tantalum-bearing granites with associated cassiterite-quartz mineralization.
The authors concluded that:
1. Accessory minerals of the wodginite group, wodginite, Ti-bearing wodginite, and rare Fe and Ti-bearing wodginite associated with Ta-bearing cassiterite and Sn-bearing tantalum-niobates, are distributed in the lithium–fluorine granites of the Eastern Desert of Egypt.
2. Three forms of wodginite crystallization were identified:
1) rims in columbite–tantalite;
2) micro-inclusions in cassiterite;
3) autonomous crystals.
The average size of wodginite crystals is 34.6 μm. Wodginite crystals represent partial or complete pseudo-morphs after tantalite-(Mn). Wodginite is marker of the transition from late-magmatic crystallization of rare-metal granitic magma to pneumatolytic mineral formation in the presence of a fluid phase.
3. Wodginite of the Nuweibi massif mainly occurs in the porphyritic granites of an additional granitic phase. It is close in composition to the worldwide wodginite of rare-metal granites, is distinguished by a reduced TiO2 content, and is a mineral indicator of rich tantalum mineralization.
4. Wodginite in the Abu Dabbab massif is replaced by Ti-bearing wodginite, and both types are maximally enriched with Mn. They are represented in all intrusive phases of the massif, and are very likely to be mineral indicators of tantalum-bearing granites with accompanying cassiterite–quartz mineralization.
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