Know all about Trondhjemite and Obsidian properties here. All properties of rocks are important as they define the type of rock and its application. Trondhjemite and Obsidian belong to Igneous Rocks.Texture of Trondhjemite is Phaneritic whereas that of Obsidian is Glassy. Trondhjemite appears Banded and Foilated and Obsidian appears Shiny. The luster of Trondhjemite is subvitreous to dull while that of Obsidian is vitreous. Trondhjemite 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 Trondhjemite are cemetery markers, creating artwork and that of Obsidian are creating artwork, mirror, used in aquariums.