Plagioclase (/ˈplædʒ(i)əˌkleɪs, ˈpleɪdʒ-, -ˌkleɪz/ PLAJ-(ee)-ə-klayss, PLAYJ-, -⁠klayz) is a series of tectosilicate (framework silicate) minerals within...

potassium, or barium. The most common members of the feldspar group are the plagioclase (sodium-calcium) feldspars and the alkali (potassium-sodium) feldspars...

and plagioclase makes up more than 65% of the total feldspar content. Gabbroids are distinguished from dioritoids by an anorthite (calcium plagioclase) fraction...

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...

phaneritic, intrusive igneous rock characterized by its composition: mostly plagioclase feldspar (90–100%), with a minimal mafic component (0–10%). Pyroxene...

contains amphibole, especially hornblende and actinolite, as well as plagioclase feldspar, but with little or no quartz. It is typically dark-colored...

quartz in plagioclase. The intergrowths are microscopic in scale, typically with maximum dimensions less than 1 millimeter. The plagioclase is sodium-rich...

plagioclase phenocrysts, but 4% olivine microphenocrysts, might be termed an aphyric to sparsely plagioclase-olivine phyric basalt, where plagioclase...

sodic plagioclase (An70–85), norites (plagioclase-orthopyroxene), and gabbronorites (plagioclase-clinopyroxene-orthopyroxene) with similar plagioclase compositions...

intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides...

Anorthite (an = not, ortho = straight) is the calcium endmember of the plagioclase feldspar mineral series. The chemical formula of pure anorthite is CaAl2Si2O8...

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...

distinguished from gabbro on the basis of the composition of the plagioclase species; the plagioclase in diorite is richer in sodium and poorer in calcium. Geologists...

Albite is a plagioclase feldspar mineral. It is the sodium endmember of the plagioclase solid solution series. It represents a plagioclase with less than...

(lamellae) of different alkali feldspars (orthoclase and sodium-rich plagioclase). Polished moonstones often display chatoyancy ("cat's eye" effect),...

percentages of quartz (crystalline silica (SiO2)), alkali feldspar, plagioclase, and feldspathoid (QAPF) are particularly important. An aphanitic (fine-grained)...

syenite is predominantly alkaline in character (usually orthoclase). Plagioclase feldspars may be present in small proportions, between 10% and 35% of...

is enriched in alkali metal oxides. Monzonite is composed mostly of plagioclase and alkali feldspar. Syenodiorite is an obsolescent term for monzonite...

porphyritic in texture, and is composed predominantly of sodium-rich plagioclase plus pyroxene or hornblende. Andesite is the extrusive equivalent of...

solutions of felsic minerals) and results in progressively sodium-rich plagioclase at lowering temperatures. In the discontinuous series mafic minerals...

(phaneritic) intrusive igneous rock similar to granite, but containing more plagioclase feldspar than orthoclase feldspar. The term banatite is sometimes used...

series dictates that during fractional crystallization, olivine and Ca-plagioclase feldspars are the first to crystalize out of a melt, after which follows...

rocks that consist predominantly of quartz, plagioclase, and alkali feldspar. Granitoids range from plagioclase-rich tonalites to alkali-rich syenites and...

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...

groundmass. The mineral assemblage is predominantly quartz, sanidine, and plagioclase. It is the extrusive equivalent of granite. Its high silica content makes...

Anorthosite – Mafic intrusive igneous rock composed predominantly of plagioclase Aplite – Fine-grained intrusive igneous rock type similar to granite...

orthoclase and plagioclase feldspars. It is typically a light colored phaneritic (coarse-grained) to porphyritic granitic rock. The plagioclase is typically...

Andesine is a silicate mineral, a member of the plagioclase feldspar solid solution series. Its chemical formula is (Ca, Na)(Al, Si)4O8, where Ca/(Ca...

medium-grained olivine-plagioclase and clinopyroxene-plagioclase gabbro consisting of a variety of minerals such as: Plagioclase Olivine Clinopyroxene/orthopyroxene...

are similar in size and carry the same charge as Ca2+, an ion found in plagioclase and other minerals. While Eu is an incompatible element in its trivalent...