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 Amphibolite Uses. We have provided you with all information about Amphibolite rock here. Amphibolite can be defined as a granular metamorphic rock which mainly consist of hornblende and plagioclase. Amphibolite is available in black, brown, green, grey colors. The streak of a rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Amphibolite is white to grey. Get to know more about Amphibolite rock and characteristics of Amphibolite rock in the next sections.