Encyclopedia > Rhyolite

  Article Content

Rhyolite

Rhyolite is the general term for a group of acidic igneous rocks, the effusive equivalent of granites. It occurs as lava flows, breccias, and in volcanic necks and dikes. In the porphyritic varieties the phenocrysts are frequently quartz or orthoclase feldspar imbedded in a highly felsitic or glassy ground mass. Rhyolites, including obsidian, frequently show flow, spherulitic, nodular, and lithophysal structures.

see also: List of minerals



All Wikipedia text is available under the terms of the GNU Free Documentation License

 
  Search Encyclopedia

Search over one million articles, find something about almost anything!
 
 
  
  Featured Article
Friedrich Christoph Dahlmann

... His last years were, however, saddened by illness, bereavement and continual friction with his colleagues. His death took place on the 5th of December 1860, following o ...