Know all about Obsidian and Trachyandesite properties here. All properties of rocks are important as they define the type of rock and its application. Obsidian and Trachyandesite belong to Igneous Rocks.Texture of Obsidian is Glassy whereas that of Trachyandesite is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular. Obsidian appears Shiny and Trachyandesite appears Dull and Soft. The luster of Obsidian is vitreous while that of Trachyandesite is earthy. Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors whereas Trachyandesite is available in black, brown, light to dark grey colors. The commercial uses of Obsidian are creating artwork, mirror, used in aquariums and that of Trachyandesite are creating artwork, pottery.