Know all about Oil shale and Obsidian properties here. All properties of rocks are important as they define the type of rock and its application. Oil shale belongs to Sedimentary Rocks while Obsidian belongs to Igneous Rocks.Texture of Oil shale is Splintery whereas that of Obsidian is Glassy. Oil shale appears Muddy and Obsidian appears Shiny. The luster of Oil shale is dull while that of Obsidian is vitreous. Oil shale is available in black, brown, buff, green, grey, red, yellow colors whereas Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. The commercial uses of Oil shale are an oil and gas reservoir and that of Obsidian are creating artwork, mirror, used in aquariums.