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Universalium. 2010.
Plagioclase — A photomicrograph of a plagioclase crystal under cross polarized light. The plagioclase crystal shows a distinct banding effect called a Polysynthetic twinning. (unknown scale) General Category … Wikipedia
plagioclase — plagioclastic /play jee euh klas tik/, adj. /play jee euh klays /, n. any of the feldspar minerals varying in composition from acidic albite, NaAlSi3O8, to basic anorthite, CaAl2Si2O8, found in most igneous rocks: shows twinning striations on… … Universalium
plagioclase — [plā′jē ō klās΄] n. [Ger plagioklas < Gr plagios (see PLAGIO ) + klasis, a cleaving, fracture < klaein, to break: see CLASTIC] any of a series of triclinic feldspars, ranging in composition from albite to anorthite and found in many rocks … English World dictionary
plagioclase — noun A group of feldspar minerals that form a solid solution series from albite (sodium aluminum silicate) to anorthite (calcium aluminum silicate). The plagioclase feldspars are found in igneous, plutonic, and metamorphic rocks. They all have… … Wiktionary
plagioclase — n. a series of feldspar minerals forming glassy crystals. Etymology: PLAGIO + Gk klasis cleavage … Useful english dictionary
feldspar — /feld spahr , fel /, n. any of a group of minerals, principally aluminosilicates of potassium, sodium, and calcium, characterized by two cleavages at nearly right angles: one of the most important constituents of igneous rocks. Also, felspar.… … Universalium
Feldspar — is the name of a group of rock forming minerals which make up as much as 60% of the Earth s crust.Feldspar. [http://www.ima na.org/about industrial minerals/feldspar.asp What is Feldspar?] Industrial Minerals Association. Retrieved on July 18… … Wikipedia
labradorite — labradoritic /lab reuh daw rit ik/, adj. /lab reuh daw ruyt , lab reuh dawr uyt/, n. a feldspar mineral of the plagioclase group, often characterized by a brilliant change of colors, with blue and green most common. [1805 15; named after LABRADOR … Universalium
Labradorite — ((Ca,Na)(Al,Si)4O8), a feldspar mineral, is an intermediate to calcic member of the plagioclase series. It is usually defined as having %An (anorthite) between 50 and 70. The specific gravity ranges from 2.71 to 2.74. The streak is white, like… … Wikipedia
Andesine — is a feldspar mineral, a part of the plagioclase series.It is usually defined as having %An between 30 and 50.Density is about 2.68.See the plagioclase main article for more information … Wikipedia
