In traditional English and North American usage, a gneiss is a coarse-grained metamorphic rock showing compositional banding (gneissic banding) but poorly developed schistosity and indistinct cleavage.

Gneiss usually forms by regional metamorphism at convergent plate boundaries. It is a high-grade metamorphic rock in which mineral grains recrystallized under intense heat and pressure.

Apr 23, 2023 · Gneiss is a foliated metamorphic rock that is a common distribute type of rock high-grade regional metamorphic approaches from pre-current formations that have been initially both igneous or sedimentary rocks. It has a glorious banding which is apparent on microscopic scale and hand specimen.

gneiss, metamorphic rock that has a distinct banding, which is apparent in hand specimen or on a microscopic scale. Gneiss usually is distinguished from schist by its foliation and schistosity; gneiss displays a well-developed foliation and a poorly developed schistosity and cleavage.

Gneiss is a coarse-grained foliated metamorphic rock that displays alternating bands of light and dark minerals, formed from high-grade metamorphism. The light minerals are typically interlocking crystals of quartz and feldspar, while the dark bands are made of mafic minerals and often display a preferred orientation.

Gneiss is a very widespread rock type, especially in the lower parts of the continental crust, but it is also a common rock on the surface in some places (Scandinavia, Canada, and other shield areas where crystalline rocks are not covered by a layer of …

Gneiss, a metamorphic rock, demonstrates a foliated texture attributed to the impact of high pressure and temperature on pre-existing rocks, such as granite, shale, or schist. The recrystallization of minerals during metamorphism leads to the development of distinct layers, manifesting as alternating bands of light and dark minerals.

Gneiss is a foliated metamorphic rock that is characterized by its banded appearance. The bands are composed of different minerals, which are aligned in parallel layers. Gneiss is formed by the high-temperature and high-pressure metamorphism of igneous or sedimentary rocks.

Dec 30, 2022 · Gneiss is a high-grade metamorphic rock known for its pronounced banding and layered appearance. This banding results from the high-temperature and high-pressure conditions under which it forms, where original rock minerals recrystallize and segregate into alternating light and dark layers.

Gneiss is a medium- to high-grade foliated metamorphic rock displaying a coarse-grained banding (also known as gneissose structure). ‘Gneiss’ derives, indeed from the German gneist, ‘spark’, likely a reference to the presence of large grains that reflect light.