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Pyroxene (diopside) crystals from Afghanistan. The pyroxenes (commonly abbreviated Px) are a group of important rock-forming inosilicate minerals found in many igneous and metamorphic rocks. Pyroxenes have the general formula XY (Si,Al)2O6, where X represents calcium (Ca), sodium (Na), iron (Fe (II)) or magnesium (Mg) and more rarely zinc ...
Diorite. Diorite (/ ˈdaɪ.əraɪt / 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. It is intermediate in composition between low-silica (mafic) gabbro and high-silica (felsic) granite.
Purely pyroxene-bearing volcanic rocks are rare, restricted to spinifex-textured sills, lava tubes and thick flows in the Archaean greenstone belts.Here, the pyroxenite lavas are created by in-situ crystallisation and accumulation of pyroxene at the base of a lava flow, creating the distinctive spinifex texture, but also occasionally mesocumulate and orthocumulate segregations.
Late-stage charnockite dykes cutting anorthosite, Rogaland, Norway Job Charnock's Mausoleum at St John's Church compound, Kolkata. Charnockite (/ ˈ tʃ ɑːr n ə k aɪ t /) is any orthopyroxene-bearing quartz-feldspar rock formed at high temperature and pressure, commonly found in granulite facies’ metamorphic regions, sensu stricto as an endmember of the charnockite series.
Jadeite is a pyroxene mineral with composition Na Al Si 2 O 6. It is hard (Mohs hardness of about 6.5 to 7.0), very tough, and dense, with a specific gravity of about 3.4. It is found in a wide range of colors, but is most often found in shades of green or white. Jadeite is formed only in the subduction zones of continental margins, where rock ...
LL chondrites, LL chondrite meteorites, Amphoterites. The LL chondrites are a group of stony meteorites, the least abundant group of the ordinary chondrites, accounting for about 10–11% of observed ordinary-chondrite falls and 8–9% of all meteorite falls (see meteorite fall statistics). The ordinary chondrites are thought to have originated ...
Augite. Augite, also known as Augurite, is a common rock-forming pyroxene mineral with formula (Ca,Na) (Mg,Fe,Al,Ti) (Si,Al)2O6. The crystals are monoclinic and prismatic. Augite has two prominent cleavages, meeting at angles near 90 degrees.
Pyroxferroite. Pyroxferroite (Fe 2+,Ca)SiO 3 is a single chain inosilicate. It is mostly composed of iron, silicon and oxygen, with smaller fractions of calcium and several other metals. [2] Together with armalcolite and tranquillityite, it is one of the three minerals which were discovered on the Moon during the 1969 Apollo 11 mission.