Gritstone is a sedimentary rock composed of coarse sand grains with inclusions of small stones. It is a coarser version of sandstone. It was laid down in the late (upper) Paleozoic era, in the Carboniferous period, in delta conditions.

Gritstone is a sedimentary rock and frequently shows signs of cross bedding or current bedding.

It is quarried for building material. British gritstone was used for millstones, to mill flour and sharpen blades, giving rise to its other common name of millstone grit.

The rock is much loved by British climbers among whom it has almost cult status and is often referred to as "God's own rock". The rough surface providing outstanding friction, allows climbers to stand on or grip the subtlest of features in the rock.

See also

• List of minerals
• List of stone

Sandsten