Know all about Diatomite and Obsidian properties here. All properties of rocks are important as they define the type of rock and its application. Diatomite belongs to Sedimentary Rocks while Obsidian belongs to Igneous Rocks.Texture of Diatomite is Clastic or Non-Clastic whereas that of Obsidian is Glassy. Diatomite appears Soft and Obsidian appears Shiny. The luster of Diatomite is dull while that of Obsidian is vitreous. Diatomite is available in grey, white, yellow colors whereas Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. The commercial uses 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 and that of Obsidian are creating artwork, mirror, used in aquariums.