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n. pl. hornfels
A fine-grained metamorphic rock composed of quartz, feldspar, mica, and other minerals, formed by the metamorphism of sedimentary rocks from heat associated with magma.
[German : Horn, horn; see hornblende + Fels, rock, cliff (from Middle High German vels, from Old High German felis).]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
(Geological Science) a hard compact fine-grained metamorphic rock formed by the action of heat from a magmatic intrusion on neighbouring sedimentary rocks. Also called: hornstone
[German: literally, horn rock]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
a dark fine-grained metamorphic rock, the result of recrystallization of siliceous or argillaceous sediments by thermal metamorphism.
[1850–55; < German, =Horn horn + Fels rock, cliff]
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
A type of granular, fine-grained metamorphic rock.
Dictionary of Unfamiliar Words by Diagram Group Copyright © 2008 by Diagram Visual Information Limited