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 Anorthosite Uses. We have provided you with all information about Anorthosite rock here. Anorthosite is a granular igneous rock composed largely of labradorite or plagioclase. Anorthosite is available in black, bluish - grey, brown, green, grey, light greenish grey, pink, white colors. The streak of a rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Anorthosite is white. Get to know more about Anorthosite rock and characteristics of Anorthosite rock in the next sections.