Last updated 2 years ago
Epidote in a granitic gneiss..The photomicrographs of the "Alps" gallery are taken from the historical collection of thin sections of rocks (labelled "AA") from the "Alto Adige" of Angelo Bianchi and Gianbattista Dal Piaz, who performed their research in the late 1920's and wrote the masterpiece memoirs on the geology and petrography of this region in 1934. A few additional photos are from the author's own collection of thin sections from the Tauern window..All pictures are taken with a digital
Talc chloritoid shist thin section
Talc Garnet Chloritoid schist. Origin: Austria. Large garnet phenocrysts (dark in crossed polars view and pink in plane polarized view) in a fine matrix of talc. Large crystals of chloritoid (green in plane polarized view) and glaucophane (blue or violet with strong pleochroism in LPNA image) are also present in the section.
A plagioclase crystal in a thin section of a fine grained dacite, in polarized light, with crossed polarizers. The crystal shows polysynthetic twinning with straight twin boundaries and concentric zones that reflect changes in composition during crystal growth. The brown and green crystals are biotite, bright yellow and pink colors are caused by secondary carbonates, small brown patches are made of iron oxides.