English: Photomicrograph (crossed polarized light) of rhyolite volcanic rock. The width of the view is approximately 3 mm. The rock shows porphyritic texture, and contains vesicles. The main phenocrysts are quartz and potassium feldspar. Groundmass is composed of quartz, potassium feldspar, volcanic glass (partly crystallized to spherulitic aggregates), iron hydroxides and chlorite. Vesicles have quartz growing on their walls, forming miarolic structure.
Eesti: Rüoliit mikroskoobi all. Vulkaaniline klaas on kristalliseeruma hakates moodustanud sfäroliitse struktuuriga kogumikke. Vesiikuleid katavad sekundaarse tekkega kvartsi mikrodruusid. Peamised fenokristallid on kvarts ning kaaliumpäevakivi.
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Siim Sepp, 2006 Volcanic rock rhyolite. Photomicrograph with crossed polars. The width of the view is approximately 0,3 mm. Porphyritic texture. Main phenocrysts are quartz and altered potassium feldspar. Groundmass is composed of quartz, p