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 Harzburgite Uses. We have provided you with all information about Harzburgite rock here. Harzburgite is a plutonic rock of the peridotite group consisting largely of orthopyroxene and olivine. Harzburgite is available in dark greenish - grey colors. The streak of a rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Harzburgite is white. Get to know more about Harzburgite rock and characteristics of Harzburgite rock in the next sections.