Plagioclase (/ˈplædʒ(i)əˌkleɪs, ˈpleɪdʒ-, -ˌkleɪz/ PLAJ-(ee)-ə-klayss, PLAYJ-, -klayz) is a series of tectosilicate (framework silicate) minerals within... 25 KB (2,888 words) - 15:41, 10 March 2024 |
Feldspar (section Plagioclase feldspars) potassium, or barium. The most common members of the feldspar group are the plagioclase (sodium-calcium) feldspars and the alkali (potassium-sodium) feldspars... 25 KB (2,434 words) - 05:08, 5 April 2024 |
effect (schiller). Labradorite is an intermediate to calcic member of the plagioclase series. It has an anorthite percentage (%An) of between 50 and 70. The... 10 KB (869 words) - 15:39, 8 April 2024 |
contains amphibole, especially hornblende and actinolite, as well as plagioclase feldspar, but with little or no quartz. It is typically dark-colored... 9 KB (1,012 words) - 14:30, 9 January 2024 |
(lamellae) of different alkali feldspars (orthoclase and sodium-rich plagioclase). Polished moonstones often display chatoyancy ("cat's eye" effect),... 5 KB (391 words) - 20:07, 23 February 2024 |
plagioclase phenocrysts, but 4% olivine microphenocrysts, might be termed an aphyric to sparsely plagioclase-olivine phyric basalt, where plagioclase... 10 KB (1,155 words) - 00:27, 20 November 2023 |
porphyritic in texture, and is composed predominantly of sodium-rich plagioclase plus pyroxene or hornblende. Andesite is the extrusive equivalent of... 25 KB (2,761 words) - 14:38, 2 March 2024 |
The anorthosite highlands of the Moon are primary crust, formed as plagioclase crystallized out of the Moon's initial magma ocean and floated to the... 11 KB (1,375 words) - 05:07, 22 April 2024 |
Albite is a plagioclase feldspar mineral. It is the sodium endmember of the plagioclase solid solution series. It represents a plagioclase with less than... 7 KB (518 words) - 23:37, 20 April 2024 |
syenite is predominantly alkaline in character (usually orthoclase). Plagioclase feldspars may be present in small proportions, between 10% and 35% of... 11 KB (1,193 words) - 23:00, 9 January 2024 |
Anorthosite – Mafic intrusive igneous rock composed predominantly of plagioclase Aplite – Fine-grained intrusive igneous rock type similar to granite... 14 KB (2,207 words) - 23:33, 16 April 2024 |
is enriched in alkali metal oxides. Monzonite is composed mostly of plagioclase and alkali feldspar. Syenodiorite is an obsolescent term for monzonite... 8 KB (895 words) - 21:51, 7 January 2024 |
solutions of felsic minerals) and results in progressively sodium-rich plagioclase at lowering temperatures. In the discontinuous series mafic minerals... 5 KB (492 words) - 01:52, 13 July 2022 |
magma chamber, although they are possible on the roofs if anorthite plagioclase is able to float free of a denser mafic melt. Cumulates are typically... 14 KB (1,748 words) - 19:00, 18 December 2023 |
rocks that consist predominantly of quartz, plagioclase, and alkali feldspar. Granitoids range from plagioclase-rich tonalites to alkali-rich syenites and... 4 KB (443 words) - 08:31, 1 March 2024 |
series dictates that during fractional crystallization, olivine and Ca-plagioclase feldspars are the first to crystalize out of a melt, after which follows... 11 KB (1,208 words) - 07:54, 14 August 2023 |
5% of the QAPF mineral fraction, plagioclase makes up 90% or more of the total feldspar content, and the plagioclase is calcium-rich (%An > 50). Hornblende... 2 KB (179 words) - 14:10, 27 July 2023 |
silicate minerals in the Bowen's Series. Rocks dominated by quartz, plagioclase, alkali feldspar and muscovite are felsic. Mafic rocks are primarily... 48 KB (5,657 words) - 16:36, 13 April 2024 |