These rocks primarily consist of quartz feldspar and mica.
Igneous rocks like granite can become gneiss.
A photograph of polished gneiss from the stock of a countertop vendor.
Granite is an igneous rock whereas gneiss is formed after metamorphosis of an existing igneous rock.
If this occurs it will now be classified as a granite.
If the chemistry and conditions are right granite forming minerals can precipitate.
Granite gneiss can also form through the metamorphism of sedimentary rocks.
Metamorphic rocks form from heat and pressure which changes the original or parent rock into a completely new rock.
Heat and pressure cause granite to become gneiss and change sandstone into quartzite.
Paragneiss is gneiss derived from sedimentary rock such as sandstone.
It forms from the slow crystallization of magma below earth s surface.
More fleshed out fuller and still correct answer.
Gneiss ˈ n aɪ s is a common and widely distributed type of metamorphic rock gneiss is formed by high temperature and high pressure metamorphic processes acting on formations composed of igneous or sedimentary rocks orthogneiss is gneiss derived from igneous rock such as granite.
The mineral constituents that create these rocks get recycled over time.
The parent rock can be either sedimentary igneous or even another metamorphic rock.
Gneiss is a metamorphic rock granite is an igneous rock and sandstone is a sedimentary rock.
The mineral composition of both granite and gneiss is same but alteration of granite because of very high pressure and temperature leads to the formation of gneiss.
All rocks undergo a series of processes called the rock cycle where one type of rock changes into another.
Not all gneiss is obtained from granite and there are also diorite.
Granite is composed mainly of quartz and feldspar with minor amounts of mica amphiboles and other minerals this mineral composition usually gives granite a red pink gray or white color with dark mineral.
