Know all about Lignite and Obsidian properties here. All properties of rocks are important as they define the type of rock and its application. Lignite belongs to Sedimentary Rocks while Obsidian belongs to Igneous Rocks.Texture of Lignite is Amorphous, Glassy whereas that of Obsidian is Glassy. Lignite appears Veined or Pebbled and Obsidian appears Shiny. The luster of Lignite is dull to vitreous to submetallic while that of Obsidian is vitreous. Lignite is available in black, brown, dark brown, grey, light to dark grey colors whereas Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. The commercial uses of Lignite are electricity generation and that of Obsidian are creating artwork, mirror, used in aquariums.