Know all about Obsidian and Itacolumite properties here. All properties of rocks are important as they define the type of rock and its application. Obsidian belongs to Igneous Rocks while Itacolumite belongs to Sedimentary Rocks.Texture of Obsidian is Glassy whereas that of Itacolumite is Clastic, Granular, Rough. Obsidian appears Shiny and Itacolumite appears Rough. The luster of Obsidian is vitreous while that of Itacolumite is dull. Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors whereas Itacolumite is available in beige, black, brown, colourless, cream, dark brown, green, grey, light green, light to dark grey, pink, red, white, yellow colors. The commercial uses of Obsidian are creating artwork, mirror, used in aquariums and that of Itacolumite are an oil and gas reservoir, in aquifers, petroleum reservoirs, soil conditioner, source of magnesia (mgo), tombstones.