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