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 Skarn Uses. We have provided you with all information about Skarn rock here. Skarns are formed during regional or contact metamorphism and from a variety of metasomatic processes involving fluids of magmatic, metamorphic, and/or marine origin. Skarn is available in black, brown, colourless, green, 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 Skarn is light to dark brown. Get to know more about Skarn rock and characteristics of Skarn rock in the next sections.