• WordNet 3.6
    • n gneiss a laminated metamorphic rock similar to granite
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Webster's Revised Unabridged Dictionary
    • n Gneiss nīs (Geol) A crystalline rock, consisting, like granite, of quartz, feldspar, and mica, but having these materials, especially the mica, arranged in planes, so that it breaks rather easily into coarse slabs or flags. Hornblende sometimes takes the place of the mica, and it is then called hornblendic gneissorsyenitic gneiss. Similar varieties of related rocks are also called gneiss.
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Century Dictionary and Cyclopedia
    • n gneiss A rock which consists essentially of the same mineral elements as granite, namely orthoclase, quartz, and mica, but in which there is a more or less distinctly foliated arrangement of the constituent minerals, and especially of the mica. It appears in a great variety of forms, and shows all stages of passage from true granite to a perfectly schistose condition, in which case the feldspar disappears, and the rock becomes a true mica schist. Porphyritic gneiss is characterized by the presence of large distinct crystals or rounded kernel-like masses of feldspar. Gneiss often contains hornblende instead of or associated with mica, and then receives the name of hornblendic or syenitic gneiss. Some gneisses are undoubtedly of eruptive origin; other varieties are admitted by most geologists to be metamorphosed sedimentary masses. As is the case with granite, so in gneiss the orthoclase is sometimes associated with plagioclase. See granite.
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Chambers's Twentieth Century Dictionary
    • n Gneiss nīs (geol.) a species of stratified rock composed of quartz, feldspar, and mica
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Webster's Revised Unabridged Dictionary
Chambers's Twentieth Century Dictionary
Ger. gneiss, a miners' word of unknown origin.


In literature:

All these minerals have once been imbedded in the granitic gneiss, which is the principal rock of the region.
"The Voyage of the Vega round Asia and Europe, Volume I and Volume II" by A.E. Nordenskieold
Everywhere granite, gneiss, or other primitive rocks, show themselves.
"Popular Adventure Tales" by Mayne Reid
Gneiss, 106; phosphoric acid in, 207.
"Manures and the principles of manuring" by Charles Morton Aikman
The rock formation is gneiss.
"Encyclopaedia Britannica, 11th Edition, Volume 3, Part 1, Slice 3" by Various
The term granite, as used commercially, includes true granite and such allied rocks as syenite and gneiss.
"The Economic Aspect of Geology" by C. K. Leith
Such is peculiarly the case with the fundamental or gneiss deposits of the period.
"The Testimony of the Rocks" by Hugh Miller
The gneiss at Knock is exceedingly various in its composition, and many of its strata the geologist would fail to recognize as gneiss at all.
"The Cruise of the Betsey" by Hugh Miller
To the south lay the trap islands; to the north and west, the gneiss ones.
"My Schools and Schoolmasters" by Hugh Miller
Chrysoberyl is known as a constituent of certain kinds of granite, pegmatite and gneiss.
"Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 3" by Various
In like manner, the Matterhorn is cut out of a block of nearly horizontal beds of gneiss.
"Modern Painters, Volume IV (of V)" by John Ruskin

In news:

The birth of a quarry and the adoption of a gneiss little rock.