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 Ganister Uses. We have provided you with all information about Ganister rock here. A ganister is a hard, fine-grained quartzose sandstone or orthoquartzite which is basically used in the manufacture of silica brick typically used to line furnaces and is a type of sedimentary rocks.. Ganister 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 Ganister is white. Get to know more about Ganister rock and characteristics of Ganister rock in the next sections.