perthitic


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perthitic

(pɜːˈθɪtɪk)
adj
(Geological Science) mineralogy relating to, consisting of, or having a similarity to perthite
References in periodicals archive ?
Lee MR, Parsons I (1995) Microtextural controls on weathering of perthitic alkali feldspars.
6%) Microcline often intergrown graphically and are sometimes perthitic with albite occurring as patchy perthite.
Pocket zones are characterized by quartz crystals, perthitic microcline, platy albite, orthoclase, biotite, lithium-iron micas and kaolinite.
The feldspar fraction is dominantly altered orthoclase feldspar and perthitic ortho-clase feldspar with traces of microcline and plagioclase.
Lee MR, Parsons I (1995) Microtextural controls of weathering of perthitic alkali feldspars.
Perthitic and myrmekitic intergrowths are observed in few sections.
Its amount increases abruptly close to the contacts of the anorthosites with silicic rocks, where perthitic alkali feldspar partly replaces plagioclase.
Detailed field and petrographic studies reveal that Jura granitoids are megaporphyritic in nature containing phenocrysts of plagioclase and perthitic feldspar.
Quartz (~ 30%) and perthitic K-feldspar (~ 60%) with subordinate albite grains is the main constituent indicating the hypersolvus character, alkali amphiboles (Table 3) in the amount of around 10 % are the only mafites, mica minerals are practically absent.
The cavities are lined with euhedral crystals of smoky quartz, greenish perthitic orthoclase .