from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A fine-grained, light-colored igneous rock, composed chiefly of feldspar and quartz.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A fine grained volcanic extrusive rock, generally light in color, composed of felsic minerals.
- n. Any light-colored volcanic rock whose true mineralogy is not yet determined.
from the GNU version of the Collaborative International Dictionary of English
- n. A finegrained rock, flintlike in fracture, consisting essentially of orthoclase feldspar with occasional grains of quartz.
from The Century Dictionary and Cyclopedia
- n. A compact, very hard rock, almost flinty in texture. made up of quartz and orthoclase feldspar intimately mixed.
fels(par) + -ite1.(American Heritage® Dictionary of the English Language, Fourth Edition)