Porphyry Paving Stone

Porphyry (rhyolite) is a magmatisches rock, one of the last Ergussprodukte widespread volcanic activity from the time of the Perms (before 270 million years) in the Adige Valley. The structure is porphyrisch, with a share of about 30-40% of Einsprenglingen in a fine or vitreous basic mass. Main ingredients are quartz, Sanidine, Plagioklase and biotite.