Quartzolite

Quartzolite or silexite is an intrusive igneous rock, in which the mineral quartz is more than 90% of the rock's felsic mineral content, with feldspar at up to 10%.: 135  Typically, quartz forms more than 60% of the rock, the rest being mostly feldspar although minor amounts of mica or amphibole may also be present. Quartzolite occurs as dykes, sills, veins, bosses and segregation masses; it is also found in association with greisen and pegmatite. Quartzolite is an extremely rare type of rock. No extrusive rock equivalent of quartzolite is known.

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.