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 Teschenite Uses. We have provided you with all information about Teschenite rock here. Teschenite is coarse- to fine-grained, dark-coloured intrusive igneous rock that usually occurs in sills, dikes and irregular masses and is always altered to some extent. Teschenite is available in dark grey to black colors. The streak of a rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Teschenite is black. Get to know more about Teschenite rock and characteristics of Teschenite rock in the next sections.