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 Felsite Uses. We have provided you with all information about Felsite rock here. Felsite is a very fine grained volcanic rock that may or may not contain larger crystals and light colored rock that typically requires petrographic examination or chemical analysis for more precise definition. Felsite is available in black, blue, brown, green, orange, red, tan, yellow colors. The streak of a rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Felsite is white. Get to know more about Felsite rock and characteristics of Felsite rock in the next sections.