Beola Argentata di Monte Gneiss Blocks
Also called Classic Gray Beola. Name according to UNI EN 12440: Beola Grigia dell'Ossola. Granitoid orthogneiss of uniform gray colour, with medium-fine grain (larger than Beola Ghiandonata), homogeneous; equigranular foliate texture and rare mineralogical lineation. The micas have a medium grain and are present in thin discontinuous layers, with regular millimeter spacing. Mineralogical composition: quartz, K-feldspar (microcline), plagioclase, biotite and muscovite in approximately equal proportions, rare chlorite and epidote.