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(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
pla•gi•o•clase(ˈpleɪ dʒi əˌkleɪs)
any of the feldspar minerals varying in composition from albite, NaAlSi3O8, to anorthite, CaAl2Si2O8.
pla`gi•o•clas′tic (-ˈklæs tɪk) adj.
Any of a series of common feldspar minerals, consisting of mixtures of sodium and calcium aluminum silicates. Plagioclase is typically white, yellow, or reddish-gray, but it can also be blue to black. It is especially common in igneous rocks.
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|Noun||1.||plagioclase - any of a series of triclinic feldspars that form rocks|
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
anorthite - rare plagioclastic feldspar occurring in many igneous rocks