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 Hornblendite Uses. We have provided you with all information about Hornblendite rock here. Hornblendite is a type of igneous plutonic rock consisting mainly of amphibole hornblende and is a type of Amphibolite rock. Hornblendite is available in black, brown, green, grey colors. The streak of a rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Hornblendite is white to grey. Get to know more about Hornblendite rock and characteristics of Hornblendite rock in the next sections.