Plagioclase Feldspar Granite

Cloud granite morton gneiss and wausau.

Plagioclase feldspar granite.

True granite according to modern petrologic convention contains both plagioclase and alkali feldspars. They are importantly dominant minerals in most igneous rock. 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. Alkali feldspar granite granite is a medium tocoarse grained acid igneous rock with essential quartz 20 and feldspar where alkali feldspar constitutes between 100 and 35 of the feldspars and minor mafic minerals.

Granite is classified according to the qapf diagram for coarse grained plutonic rocks and is named according to the percentage of quartz alkali feldspar orthoclase sanidine or microcline and plagioclase feldspar on the a q p half of the diagram. They are major constituents in a wide range of intrusive and extrusive igneous rocks including granite diorite gabbro rhyolite andesite and basalt. 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. The names of the minerals in the series are arbitrarily given based upon their relative abundance of albite and anorthite.

Plagioclase feldspar group minerals are the most common rock forming minerals. Plagioclase is a series of tectosilicate framework silicate minerals within the feldspar group. When a granitoid is devoid or nearly.