Arkoses
Arkose sandstone (arkose) is a clastic sedimentary rock of the sandstone type, consisting of quartz grains and orthoclase . The grain size is like ordinary sand .
It is formed during the destruction of granite , gneiss and other igneous granular rocks that have undergone weathering .
The composition of the arkoses includes grains of quartz, feldspars, and partly mica, which are cemented by clay or micaceous minerals, silica , and iron hydroxides.