Plagioclase is the name of a group of feldspar minerals that form a solid solution series ranging from pure albite, Na(AlSi 3 O 8), to pure anorthite, Ca(Al 2 Si 2 O 8). Minerals in this series are a homogenous mixture of albite and anorthite.

Rather than referring to a particular mineral with a specific chemical composition, plagioclase is a continuous solid solution series, more properly known as the plagioclase feldspar series. This was first shown by the German mineralogist Johann Friedrich Christian Hessel (1796–1872) in 1826.

Aug 11, 2018 · Overview of physical properties, chemistry, structure, occurence and mineralogy of feldspar. Description of major members like anorthite, albite, plagioclase, orthoclase, sanicine and microcline.

Plagioclase feldspars are a continuous mineral series in which calcium and sodium substitute for one another in the same crystal structure. Because they share a similar crystal structure, all the plagioclase varieties exhibit very similar properties and …

Apr 23, 2023 · Plagioclase is a continuous series of solid solutions known as the plagioclase feldspar series, rather than a specific mineral with a particular chemical composition. The series ranges from albite to anorthite endmembers (with respective compositions NaAlSi3O8 to CaAl2Si2O8), where sodium and calcium atoms can substitute for each other in the ...

Apr 19, 2024 · 斜长石（Plagioclase Feldspar）： 是一个连续的矿物系列，其化学成分在钠长石（Na [AlSi3O8]）和钙长石（Ca [Al2Si2O8]）之间变化，故称斜长石固溶体系列。 斜长石出现在广泛的火成岩类型中，包括中性至基性火成岩（如辉长岩、闪长岩和安山岩），以及某些变质岩中。 斜长石根据钠钙比例不同，进一步细分为多个亚种，如 albite（钠长石）、andesine（中长石）、labradorite（拉长石）、bytownite（倍长石） 和 anorthite（钙长石）等。 斜长石的物理性质 …

plagioclase, any member of the series of abundant feldspar minerals usually occurring as light-coloured, glassy, transparent to translucent, brittle crystals.

Plagioclase (a feldspar) is widespread and common in a wide variety of igneous and metamorphic rocks and, to a much lesser extent, in some immature sedimentary rocks. In general, keys to identifying plagioclase are its (lack of) color, its low birefreingence, and its twinning.

The plagioclase feldspar family is the most common mineral family in the earth’s crust. It is almost ubiquitous in igneous rocks. Gabbros, basalts and anorthosites tend to have more calcium-rich plagioclase, generally labradorite. Andesites and diorite tend to have moderately sodium-rich plagioclase, usually in the andesine range.

Feldspar (/ ˈ f ɛ l (d) ˌ s p ɑːr / FEL(D)-spar; sometimes spelled felspar) is a group of rock-forming aluminium tectosilicate minerals, also containing other cations such as sodium, calcium, potassium, or barium. [3] The most common members of the feldspar group are the plagioclase (sodium-calcium) feldspars and the alkali (potassium-sodium) feldspars. [4] ...