Mafic Minerals In Granite

Felsic minerals are usually light in color and have specific gravities less than 3 0.

Mafic minerals in granite.

Common rock forming mafic minerals include olivine pyroxene amphibole biotite and other micas augite and the calcium rich plagioclase feldspars. Common felsic minerals include quartz muscovite mica and the orthoclase feldspars. The most common felsic rock is granite which represents the purified end product of the earth s internal differentiation process. Often the species of mafic minerals is included in the name for instance hornblende bearing granite pyroxene tonalite or augite megacrystic monzonite because the term granite already assumes content with feldspar and quartz.

Vey of opaque mineral assemblages and mafic mineral chemistry in the same specimens from which i and s type granite classification was developed was under taken to clarify this situation. These minerals are high in magnesium and ferric oxides and their presence gives mafic rock its characteristic dark colour. It is formed by the slow cooling and crystallisation of magma below the earths surface in a pluton. The rock texture thus determines the basic name of a felsic rock.

Mafic is a term used to describe both minerals that are rich in iron and magnesium and rocks that are rich in those minerals. Common examples of mafic minerals include olivine biotite hornblende. Granite is a felsic composed of light coloured feldspars and silica minerals intrusive rock. In terms of chemistry mafic rocks are on the other side of the rock spectrum from the so called felsic rocks.

Mafic rock is commonly contrasted with felsic rock in which.