gneiss

[ nahys ]

noun
  1. a metamorphic rock, generally made up of bands that differ in color and composition, some bands being rich in feldspar and quartz, others rich in hornblende or mica.

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Origin of gneiss

1
Borrowed into English from German around 1750–60

Other words from gneiss

  • gneissic, adjective

Words that may be confused with gneiss

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British Dictionary definitions for gneiss

gneiss

/ (naɪs) /


noun
  1. any coarse-grained metamorphic rock that is banded and foliated: represents the last stage in the metamorphism of rocks before melting

Origin of gneiss

1
C18: from German Gneis, probably from Middle High German ganeist spark; related to Old Norse gneista to give off sparks

Derived forms of gneiss

  • gneissic, gneissoid or gneissose, adjective

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for gneiss

gneiss

[ nīs ]


  1. A highly foliated, coarse-grained metamorphic rock consisting of light-colored layers, usually of quartz and feldspar, alternating with dark-colored layers of other minerals, usually hornblende and biotite. Individual grains are often visible between layers. Gneiss forms as the result of the regional metamorphism of igneous, sedimentary, or other metamorphic rocks.

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