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