Alkali feldspar granite, some varieties of which are called 'red granite', [1] is a felsic igneous rock and a type of granite rich in the mineral potassium feldspar (K-spar). It is a dense rock with a phaneritic texture.

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.

Alkali feldspars are fundamental rock-forming K- and Na-bearing aluminosilicates that occur in many igneous, metamorphic, and sedimentary rocks, and constitute a significant portion of the ‘granitic’ continental crust.

Granite (/ ˈ ɡ r æ n ɪ t / GRAN-it) is a coarse-grained intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies underground.

Alkali feldspar granites are the alkali feldspar-rich end.member of granites. They are felsic plutonic igneous rocks consisting essentially of quartz (20-60% of the felsic minerals) and alkali feldspar (> 90% of feldspars). Due to the high K-feldspar content, this rock tends to …

A light-coloured granitoid (a coarse grained igneous rock composed mostly of quartz, alkali-feldspar and sodic plagioclase), where plagioclase is less than 10% of the total feldspar on the QAPF diagram. Rocks in section 2 of the QAPF diagram. A subgroup of the Feldspar Group, poor in calcium, and mostly rich in potassium.

The granite that contains large K-feldspar grains of spherical shape and pink or reddish color is known as porphyritic granite, and rapakivi granite (large rounded crystals of orthoclase/oligoclase feldspar) (Figs. 5.12 and 5.13).

2015年9月1日 · Quartz, feldspar and biotite are the major minerals in the alkali-feldspar granite and the albite granite. All the feldspars from the two types of granites are depleted in CaO, and therefore alkali-feldspars are dominant in these rocks.

2025年1月1日 · The alkali feldspars are primarily important as constituents of rocks; they are very widespread and abundant in alkali and acidic igneous rocks (particularly syenites, granites, and granodiorites), in pegmatites, and in gneisses.

Alkali feldspar granite: "A special term for a variety of granite in which plagioclase is less than 10% of the total feldspar."