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Diorite (/ ˈ d aɪ. ə r aɪ t / DY-ə-ryte) [1] [2] is an intrusive igneous rock formed by the slow cooling underground of magma (molten rock) that has a moderate content of silica and a relatively low content of alkali metals.
Hornblende diorite from the Henry Mountains, Utah, US. Hornblende is a common constituent of many igneous and metamorphic rocks such as granite, syenite, diorite, gabbro, basalt, andesite, gneiss, and schist. It crystallizes in preference to pyroxene minerals from cooler magma that is richer in silica and water. [13]
Vivianite is a secondary mineral found in a number of geologic environments: the oxidation zone of metal ore deposits, in granite pegmatites containing phosphate minerals, in clays and glauconitic sediments, and in recent alluvial deposits replacing organic material such as peat, lignite, bog iron ores and forest soils (all).
Another aspect of granite classification is the ratios of metals that potentially form feldspars. Most granites have a composition such that almost all their aluminum and alkali metals (sodium and potassium) are combined as feldspar. This is the case when K 2 O + Na 2 O + CaO > Al 2 O 3 > K 2 O + Na 2 O. Such granites are described as normal or ...
Quartz diorite is an igneous, plutonic rock, of felsic composition, with phaneritic texture. Feldspar is present as plagioclase (typically oligoclase or andesine ) with 10% or less potassium feldspar.
Magnetite is a mineral and one of the main iron ores, with the chemical formula Fe 2+ Fe 3+ 2 O 4. It is one of the oxides of iron , and is ferrimagnetic ; [ 6 ] it is attracted to a magnet and can be magnetized to become a permanent magnet itself.
Dacite (/ ˈ d eɪ s aɪ t /) is a volcanic rock formed by rapid solidification of lava that is high in silica and low in alkali metal oxides. It has a fine-grained to porphyritic texture and is intermediate in composition between andesite and rhyolite. It is composed predominantly of plagioclase feldspar and quartz.
It is an iron-magnesium orthosilicate with the variable formula (Mg,Fe) 2 SiO 4. The magnesium-rich olivine of peridotites is typically olive-green in color. [20] Pyroxenes are chain silicates having the variable formula (Ca,Na,Fe II,Mg)(Cr,Al,Fe III,Mg,Mn,Ti,V)Si 2 O 6 comprising a large group of different