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 Greenschist Uses. We have provided you with all information about Greenschist rock here. Greenschist is a metamorphic rock that is formed under lowest temperatures and pressures and is usually produced by regional metamorphism. Greenschist is available in dark greenish - grey, green colors. The streak of a rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Greenschist is white. Get to know more about Greenschist rock and characteristics of Greenschist rock in the next sections.