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n. A fine-grained extrusive volcanic rock, similar to granite in composition and usually exhibiting flow lines.

n. An igneous, volcanic (extrusive) rock, of felsic composition, with aphanitic to porphyritic texture.

n. A quartzose trachyte, an igneous rock often showing a fluidal structure.

n. The name given by Richthofen to certain rocks occurring in Hungary which resemble trachyte, but are distinguished from it by the presence of quartz as an essential ingredient, and also by a great variety of texture, showing more distinctly than rocks usually do that the material had flowed while in a viscous state.

n. very acid volcanic rock

"Left long enough, this magma erupts as a substance known as rhyolite - a very pale yellow or grey rock which is responsible for the beautiful colours in Landmannalaugar and Yellowstone in the US."

igneous rock   

sand-strewn    Precambrian    know    over-hanging    port    high-hung    knife-like    syenite    shelflike    quartzite