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 Monzonite Uses. We have provided you with all information about Monzonite rock here. Monzonite is a granular igneous rock with composition between syenite and diorite and containing approximately equal amounts of orthoclase and plagioclase. Monzonite is available in black, brown, light to dark grey, white colors. The streak of a rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Monzonite is white. Get to know more about Monzonite rock and characteristics of Monzonite rock in the next sections.