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The name pyroxene is derived from the Ancient Greek words for 'fire' (πυρ, pur) and 'stranger' (ξένος, xénos). Pyroxenes were so named due to their presence in volcanic lavas, where they are sometimes found as crystals embedded in volcanic glass; it was assumed they were impurities in the glass, hence the name meaning "fire stranger ...
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.
The word pyroxene, in turn comes from the Greek words for fire (πυρ) and stranger (ξένος). Pyroxenes were named this way because of their presence in volcanic lavas, where they are sometimes seen as crystals embedded in volcanic glass ; it was assumed they were impurities in the glass, hence the name "fire strangers".
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.
Some forms of actinolite are used as gemstones. One is nephrite, one of the two types of jade (the other being jadeite, a variety of pyroxene). [5] Another gem variety is the chatoyant form known as cat's-eye actinolite. This stone is translucent to opaque, and green to yellowish green color. This variety has had the misnomer jade cat's-eye ...
Pyroxene, ilmenite, magnetite, and olivine are the mafic minerals most commonly present. Anorthosites are of enormous geologic interest, because it is still not fully understood how they form. Most models involve separating plagioclase crystals based on their density. Plagioclase crystals are usually less dense than magma; so, as plagioclase ...
When Devanāgarī is used for writing languages other than Sanskrit, conjuncts are used mostly with Sanskrit words and loan words. Native words typically use the basic consonant and native speakers know to suppress the vowel when it is conventional to do so. For example, the native Hindi word karnā is written करना (ka-ra-nā). [60]
Euhedral crystal of augite from Teide (4.4 x 3.0 x 2.3 cm). Augite is a solid solution in the pyroxene group. Diopside and hedenbergite are important endmembers in augite, but augite can also contain significant aluminium, titanium, and sodium and other elements.