Rocks are naturally occurring solids which are composed of minerals & have been used by humans since ages. From Stone Age, rocks are used for various purposes. Also, the metals and minerals found in rock play an important role in our life. Get to know all the Gritstone Uses. We have provided you with all information about Gritstone rock here. Gritstone or grit is a hard, coarse-grained, siliceous sandstone. Gritstone is available in beige, black, brown, colourless, cream, dark brown, green, grey, light green, light to dark grey, pink, red, white, yellow colors. The streak of a rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Gritstone is white. Get to know more about Gritstone rock and characteristics of Gritstone rock in the next sections.