Sandstone is a sedimentary rock composed mainly of sand-size mineral or rock grains. Most sandstone is composed of quartz andor feldspar because these are the most common minerals in earth's crust.
Granites are usually a white, black or buff color and are medium to coarse grained, occasionally with some individual crystals larger than the groundmass forming a rock known as porphyry.
Slate is a fine-grained, homogeneous, metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low grade regional metamorphism.
Limestones often contain variable amounts of silica in the form of chert or flint, as well as varying amounts of clay, silt and sand as disseminations, nodules, or layers within the rock.
Gwalior, Madhya Pradesh, India
