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