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Mineralogia Polonica 2004
The first occurrence of elbaite in PolandKeywords: tourmaline , elbaite , the Góry Sowie gneissic block , Lower Silesia , Poland Abstract: An amphibolite-hosted quartzo-feldspar-mica pegmatite with schorl, green elbaite, spessartine,andalusite, spinel, hyalophane, zircon, columbite and beryl was found near Gilów in the E part of theGóry Sowie gneissic block (Lower Silesia, Poland). The black tourmaline crystals are chracterized by thechange of their composition from Mg- and Al-enriched schorl, typical of the Góry Sowie block, to Al- and,Al- and Li-enriched schorl, and to Fe-bearing elbaite. Light green tourmaline corresponds to (Fe,Mn)--bearing elbaite. The crystallization sequence of the tourmaline varieties results from progressive change ofcomposition of pegmatite melts in the last metamorphic stage of a parent sedimentary protolith around370–380 Ma ago. The stage of Li-bearing tourmaline formation corresponds to crystallization of a phosphateassemblage with ferrisicklerite-sarcopside-graftonite lamellar intergrowths known from other pegmatites ofthe Góry Sowie block.
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