Rhyolite
Granite contains plagioclase feldspar and potassium feldspar. It really depends on the composition of the magma from which it forms. If the granite has a lot of pink in it, chances are it is potassium feldspar (K-Spar). If it is dominated by white, then the feldspar is probably plag.
Plagioclase feldspar is a non-metallic mineral. It has 2 cleavages at nearly right angles. It is also differentiated from potassium feldspar because it contains striations. Potassium feldspar has 2 cleavages at nearly right angles.
There are broadly three main types of feldspars: calcium, sodium and potassium. They have the following general chemical formulas:KAlSi3O8 - NaAlSi3O8 - CaAl2Si2O8The endmember mineral states are known as K-Feldspar, Albite and Anorthite which are the potassium, sodium and calcium feldspars respectively.There can be a mix of calcium and sodium (more correctly termed solid solutions) in Feldspars between Albite and Anorthite which are known generally as Plagioclase feldspars.For more information please see the related question
Feldspars are classified based on their chemical composition into three main groups: potassium feldspar, plagioclase feldspar, and sodium feldspar. Potassium feldspar includes orthoclase and microcline, while plagioclase feldspar includes albite, oligoclase, and labradorite. Sodium feldspar primarily consists of albite. Each type of feldspar has a unique mineral structure and varying ratios of sodium, potassium, and calcium ions.
potassium-argon
Granite always contains the minerals quartz, feldspar (potassium feldspar or plagioclase feldspar), and mica (biotite or muscovite). These minerals give granite its characteristic appearance and properties.
It depends on the type of feldspar. Potassium Feldspar (also called K-Spar), contains potassium, aluminum, silicate: KAlSi3O8. Plagioclase Feldspar, on the other hand, contains calcium or sodium, aluminum, and silicate: NaAlSi3O8 or CaAl2Si2O8.
Basalt contains minerals such as plagioclase feldspar, pyroxene, and olivine. Gabbro also contains plagioclase feldspar and pyroxene, but generally has a coarser texture due to slower cooling rates underground.
Basalt contains the greatest quantity of the mineral plagioclase feldspar.
Granite is a rock containing both amphibole and potassium feldspar.
A Diorite.
Quartz, Potassium Feldspar, Plagioclase Feldspar, Muscovite (mica), Biotite (mica), Amphibole (hornblende), Pyroxene, Olivine, Calcite, Dolomite.