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Diorite is coarse – grained intrusive igneous rock that commonly mineralogy is plagioclase feldspar and dark colored minerals such as hornblende and biotite.It usually occurs dikes, sills and intrusions with continental crust . Diorite is usually grey to dark-grey in colour, but it can also be black or bluish-grey, and frequently has a greenish cast.
Diorite is intrusive igneous rock cause we can see minerals on naked eyes and also plutonic rock to phonetic texture.
Diorite composition principally of the silicate minerals plagioclase feldspar (typically andesine), biotite, hornblende, and/or pyroxene. The chemical composition of diorite is intermediate, between that of maficgabbro and felsic granite.
It may contain small amounts of quartz, microcline,and olivine. Zircon, apatite, titanite, magnetite, ilmenite, and sulfides occur as accessory minerals
Uses of Diorite
- It is used as construction material of roads, buildings and also drainage stone for erosion control
- In the dimension stone industry
Formation of Diorite
Partial melting of the oceanic plate produces a basaltic magma that rises and intrudes the granitic rock of the continental plate. There, the basaltic magma mixes with granitic magmas or melts granitic rock as it ascends through the continental plate. This produces a melt that is intermediate in composition between basalt and granite. Diorite forms if this type of melt crystallizes below the surface.
It has coarse-grained textures usually show that slowly cooled deep underground. As a result of this slow cooling gives crystals enough time to grow to easily seen size. Size of growt larger than 1mm.
Diorite and Andesite
Diorite is phaneritic, or coarse grained, and forms at depth when andesitic magma has lots of time to crystallize. This allows for more ion transport, leading to much larger crystals than the ones you’d find in andesite.
Andesite usually forms closer to the surface. While it’s not volcanic (in which case it would likely be pumice or obsidian), it does require a much quicker crystallization process. This leads to its aphanitic, or fine-grained, texture, which make easy to differentiate from diorite.
Diorite and Granodiorite
Granodiorite, medium- to coarse-grained rock this is a number of the most considerable intrusive igneous rocks. It consists of quartz and is outstanding from granite through its having extra plagioclase feldspar than orthoclase feldspar; its other mineral constituents include hornblende, biotite, and augite. The plagioclase (andesine) commonly paperwork twinned crystals, on occasion wholly encased via orthoclase. The mode of formation and occurrence, physical look, and mineralic composition and texture of granodiorite are much like those of granite (q.V.); granodiorite is darker in color, but, due to its more plagioclase content.