What is arkose in geology ?

Arkose : definition

Arkose is a detrital sedimentary rock containing a majority of quartz grains and at least 25% of feldspar grains. Micas are frequent, with an essentially clayey cement. These frequently continental rock outcrops near the granito-gneissic basements from which they are derived by weathering and erosion.
 
It is a rock that can be used in construction, Montpeyroux (Puy-de-Dôme), one of the most beautiful villages in France is entirely built in arkose.