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 Blueschist Uses. We have provided you with all information about Blueschist rock here. Blueschist is a metamorphic rock which is generally blue in color and is formed under conditions of high pressure and low temperature. Blueschist is available in blue, bluish - grey, purple, shades of blue colors. The streak of a rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Blueschist is white to grey. Get to know more about Blueschist rock and characteristics of Blueschist rock in the next sections.