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 Pegmatite Uses. We have provided you with all information about Pegmatite rock here. Pegmatite rock is a holocrystalline, intrusive igneous rock which is composed of interlocking phaneritic crystals. Pegmatite is available in black, brown, cream, green, grey, pink, red, rust, silver, white, yellow colors. The streak of a rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Pegmatite is white. Get to know more about Pegmatite rock and characteristics of Pegmatite rock in the next sections.