Tourmaline vs. rare-element mineralization in the Velká Bíteš pegmatite field, Czech Republic

Rare-element pegmatites (with elevated contents of Li, Sn, Ta, and W) were studied at four localities: Osova Bitýska, Vlkov, Křižinkov and Křovi. Pegmatite at Osova Bitýska has Li mineralization (lepidolite, tourmaline) and high contents of F, Rb, Cs and elevated Sn (lepidolite, topaz, tourmaline, phosphates). Pegmatite of Vlkov contains elevated Nb (oxides) and F (tourmaline). The pegmatite Křižinkov 2 contains elevated REE and Zr (monazite, zircon, xenotime, cheralite) and increased contents of Nb and F (columbite, tourmaline). The Li-pegmatite at Křižinkov is well fractionated, contains elevated Li, F, Sn, and W (tourmaline – elbaite, cassiterite, wodginite, ixiolite); similar degree of fractionation is in the adjacent pegmatite at Křovi. All studied pegmatites have tourmalines with high contents of Fe and F and very low contents of Mg, indicating their increased fractionation.