dacite
[ dā′sīt′ ]
A fine-grained light gray volcanic rock consisting primarily of quartz, plagioclase feldspar, and potassium feldspar, and also containing biotite, hornblende, or pyroxene. It is the fine-grained equivalent of granodiorite.
The American Heritage® Science Dictionary
Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Examples from the Web for dacite
Dacite is the lava of Krakatoa and some of the volcanoes of Japan.
Volcanoes: Past and Present|Edward HullI wonder if they are visible from the dacite elevation on which SHE lives.
Of All Things|Robert C. BenchleyThe lavas and ashes ejected by these volcanoes consist of liparite, dacite, andesite and basalt.