gneiss
About Our Definitions: All forms of a word (noun, verb, etc.) are now displayed on one page.
About Our Definitions: All forms of a word (noun, verb, etc.) are now displayed on one page.gneiss
noun \ˈnīs\Definition of GNEISS
: a foliated metamorphic rock corresponding in composition to a feldspathic plutonic rock (as granite)
— gneiss·ic \ˈnī-sik\ adjective
— gneiss·oid \-ˌsȯid\ adjective
— gneiss·ose \-ˌsōs\ adjective
See Origin of GNEISS
German Gneis, alteration of Middle High German gneiste spark, from Old High German gneisto; akin to Old English fȳrgnāst spark
First Known Use: 1757
gneiss
noun (Concise Encyclopedia)Medium- to coarse-grained metamorphic rock with parallel, somewhat irregular banding that has little tendency to split along planes. Gneiss is the principal rock over extensive metamorphic terrains. Orthogneiss is formed by the metamorphism of igneous rocks; paragneiss results from the metamorphism of original sedimentary rocks. Pencil gneiss contains rod-shaped individual minerals or segregations of minerals, and augen gneiss contains large lenticular mineral grains or mineral aggregates having the appearance of eyes scattered through the rock.
Learn More About GNEISS
Browse
Next Word in the Dictionary: Gnesio–Lutheran
Previous Word in the Dictionary: gnd
All Words Near: gneiss
Previous Word in the Dictionary: gnd
All Words Near: gneiss
Seen & Heard 
What made you want to look up gneiss? Please tell us where you read or heard it (including the quote, if possible).
