Metamorphic Granite Rock Mica Quartz
These minerals make up more than 80 of the rock.
Metamorphic granite rock mica quartz. Other common minerals include mica muscovite and biotite and hornblende see amphibole. Rocks make up the majority of the earth s crust. Granite was formed when magma cooled slowly forming crystals of the four minerals that make up the rock granite. It is usually composed primarily of the minerals quartz feldspar and mica.
It forms when a quartz rich sandstone is altered by the heat pressure and chemical activity of metamorphism. When granite is subjected to intense heat and pressure it changes into a metamorphic rock called gneiss. Granite is a light colored igneous rock with grains large enough to be visible with the unaided eye. The united kingdom virtual microscope ukvm collection consists of igneous sedimentary and metamorphic rocks from around the uk.
Bands of interlocking quartz grains and some feldspar plagioclase and alkali lamellar twinning and alteration alternate with bands composed of needles of biotite mica and muscovite mica about 50 50. One of the most common rock is granite. 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. It consists of coarse grains of quartz 10 50 potassium feldspar and sodium feldspar.
Strictly speaking granite is an. Look at the photo above of granite. These conditions recrystallize the sand grains and the silica cement that binds them together. The four minerals that make up granite are feldspar quartz mica and hornblende.
It forms from the slow crystallization of magma below earth s surface. Granite ˈ ɡ r æ n ɪ t is a common type of felsic intrusive igneous rock that is granular and phaneritic in texture. Quartz displays undulose extinction and being the most soluble mineral in this rock has recrystallised into the pressure shadows around the. It is intended as a teaching resource helping to tell the story of the common rock types and how they form and reflecting the history of the uk at the margins of the continent of europe.
Slate is another common metamorphic rock that forms from shale. Granite is a light colored plutonic rock found throughout the continental crust most commonly in mountainous areas.