Know all about Obsidian and Diatomite properties here. All properties of rocks are important as they define the type of rock and its application. Obsidian belongs to Igneous Rocks while Diatomite belongs to Sedimentary Rocks.Texture of Obsidian is Glassy whereas that of Diatomite is Clastic or Non-Clastic. Obsidian appears Shiny and Diatomite appears Soft. The luster of Obsidian is vitreous while that of Diatomite is dull. Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors whereas Diatomite is available in grey, white, yellow colors. The commercial uses of Obsidian are creating artwork, mirror, used in aquariums and that of Diatomite are alumina refineries, animal feed filler, as a feed additive for livestock, creating artwork, drawing on blackboards, fire resistant, gymnasts, athletes and mountain climbers use for grip, in aquifers, soil conditioner, to ignite fire, used as a filter medium, used as an insecticide, whiting material in toothpaste, paint and paper.