Know all about Tonalite and Obsidian properties here. All properties of rocks are important as they define the type of rock and its application. Tonalite and Obsidian belong to Igneous Rocks.Texture of Tonalite is Phaneritic whereas that of Obsidian is Glassy. Tonalite appears Banded and Foilated and Obsidian appears Shiny. The luster of Tonalite is subvitreous to dull while that of Obsidian is vitreous. Tonalite is available in black, brown, light to dark grey, white colors whereas Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. The commercial uses of Tonalite are cemetery markers, creating artwork and that of Obsidian are creating artwork, mirror, used in aquariums.