plagioclase

pla·gi·o·clase  (plj--kls, -klz, plj-)

n.

Any of a common rock-forming series of triclinic feldspars, consisting of mixtures of sodium and calcium aluminum silicates. Also called oligoclase.

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[Greek plagio-, plagio- + Greek klasis, breaking (from its oblique cleavage) (from kln, to break).]

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plagioclase [ˈpleɪdʒɪəʊˌkleɪz]

n

(Earth Sciences / Minerals) a series of feldspar minerals consisting of a mixture of sodium and calcium aluminium silicates in triclinic crystalline form: includes albite, oligoclase, and labradorite

plagioclastic  [ˌpleɪdʒɪəʊˈklæstɪk] adj

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plagioclase  (plj--kls)

Any of a series of common feldspar minerals, consisting of differing mixtures of sodium and calcium aluminum silicates. Plagioclase is typically white, yellow, or reddish-gray, but it can also be blue to black. It occurs in igneous rocks. The minerals albite, oligoclase, andesine, labradorite, bytownite, and anorthite are all plagioclases. Chemical formula: (Na,Ca)Al(Si,Al)Si₂O₈.

Thesaurus

Noun

1.

plagioclase - any of a series of triclinic feldspars that form rocks oligoclase dacite - a grey volcanic rock containing plagioclase and quartz and other crystalline minerals basalt - the commonest type of solidified lava; a dense dark grey fine-grained igneous rock that is composed chiefly of plagioclase feldspar and pyroxene feldspar, felspar - any of a group of hard crystalline minerals that consist of aluminum silicates of potassium or sodium or calcium or barium albite, white feldspar - a widely distributed feldspar that forms rocks anorthite - rare plagioclastic feldspar occurring in many igneous rocks