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 Shoshonite Uses. We have provided you with all information about Shoshonite rock here. Shoshonite is a basaltic rock, properly a potassic trachyandesite, composed of olivine, augite and plagioclase phenocrysts in a groundmass with calcic plagioclase and sanidine and some dark-colored volcanic glass. Shoshonite is available in brown- black, dark brown colors. The streak of a rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Shoshonite is white to grey. Get to know more about Shoshonite rock and characteristics of Shoshonite rock in the next sections.