Sandstone
Topic: Minerals, Rocks and the Rock Cycle · NCERT: Beyond NCERT
Meaning
Sandstone is a clastic sedimentary rock, meaning it is made of broken rock grains. Its grains are the size of sand and are mostly quartz. Silica, calcite or iron oxide cements the grains together. Iron oxide gives some sandstone its red colour. Sandstone is porous (it has tiny spaces between the grains), so it can store groundwater, oil and gas. It is easy to cut, which makes it a popular building stone.
Example
Red Vindhyan sandstone from central India was used to build the Red Fort (Delhi), Fatehpur Sikri (near Agra, Uttar Pradesh) and the Sanchi stupa (Madhya Pradesh).
Don't confuse with
- Quartzite: sandstone is a sedimentary rock whose grains can be rubbed apart. Quartzite forms when heat and pressure change sandstone. Its grains fuse into a very hard rock that breaks right through the grains.
Related concepts
- Sedimentary rock
- Lithification
- Clastic, chemical and organic sedimentary rocks
- Banded iron formation