Black Granite Minerals

Strictly speaking granite is an.

Black granite minerals.

Granite ˈ ɡ r æ n ɪ t is a common type of felsic intrusive igneous rock that is granular and phaneritic in texture. Granite is the most common intrusive rock in earth s continental crust it is familiar as a mottled pink white gray and black ornamental stone it is coarse to medium grained. The pink grains are orthoclase feldspar and the clear to smoky grains are quartz or muscovite. White granite is a granite that is composed primarily of quartz milky white and feldspar opaque white minerals.

The crystals in granite provide a variety of mixed colors feldspar pink or red mica dark brown or black quartz clear pink white or black and amphibole black. Crystals are common with striated faces shaped in octahedrons or dodecahedrons. Granites can be predominantly white pink or gray in color depending on their mineralogy the word granite comes from the latin granum a grain in reference to the coarse grained structure of such a completely crystalline rock. The grain size is coarse enough to allow recognition of the major minerals.

It may be gray black or have a rusty coating. Look for a black streak and a strong attraction to a magnet. It is about two inches across. The specimen above is a typical granite.

Granite is high in quartz about 25 feldspar and mica. The small black specks in the granite above are likely small amphibole grains. Its three main minerals are feldspar quartz and mica which occur as silvery muscovite or dark biotite or both. Numerous other minerals can be present in granite.