Oligoclase is a rock-forming mineral belonging to the plagioclase feldspars. The Mohs hardness is 6-6.5 and the specific gravity is 2.64-2.66. In color it is usually white, with shades of grey, green, or red.
Sandstone is a clastic sedimentary rock composed mainly of sand-sized minerals or rock grains. Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any color, but the most common colors are tan, brown, yellow, red, grey, pink, white, and black.