Know all about Hornfels and Obsidian properties here. All properties of rocks are important as they define the type of rock and its application. Hornfels belongs to Metamorphic Rocks while Obsidian belongs to Igneous Rocks.Texture of Hornfels is Granular, Platy whereas that of Obsidian is Glassy. Hornfels appears Dull and Obsidian appears Shiny. The luster of Hornfels is shiny while that of Obsidian is vitreous. Hornfels is available in brown, dark greenish - grey, green, reddish brown colors whereas Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. The commercial uses of Hornfels are cemetery markers, commemorative tablets, creating artwork and that of Obsidian are creating artwork, mirror, used in aquariums.