A rare mineral-bearing pegmatite from the Szklary serpentinite massif, the Fore-Sudetic Block, SW Poland

Abstract

In the Szklary serpentinite massif, besides serpentinites, amphibolites, rare rodingites and altered gabbros, rather common light-coloured aplites occur. Occurrences of pegmatites are very rare. A small fragment of a pegmatite, basically composed of feldspars, quartz, micas and tourmaline, is exposed only on Mt. Szklana. During detailed mineralogical investigations on it, numerous and sometimes rare or very rare minerals have been identified: chrysoberyl, spessartine, manganocolumbite and manganotantalite, stibiocolumbite, holtite, pyrochlore, beusite, paradocrasite and stibarsen, manganoan apatite and others, occurring in small or very small grains. The pegmatite from Szklary probably represents a product of the crystallization of silicic magma generated from the partial melting of older sediments during high-grade metamorphism. Its structural and textural development (graphic intergrowths), and to some extent its mineral composition make it comparable to some anatectic pegmatites of the gneissic block of the Góry Sowie Mts.