Know all about Gneiss and Flint properties here. All properties of rocks are important as they define the type of rock and its application. Gneiss belongs to Metamorphic Rocks while Flint belongs to Sedimentary Rocks.Texture of Gneiss is Banded, Foliated, Platy whereas that of Flint is Banded, Rough. Gneiss appears Foliated and Flint appears Glassy or Pearly. The luster of Gneiss is dull while that of Flint is vitreous. Gneiss is available in black, brown, pink, red, white colors whereas Flint is available in black, brown, green, grey, red, white colors. The commercial uses of Gneiss are cemetery markers, jewelry, tombstones, used in aquariums and that of Flint are creating artwork, gemstone, in fire-starting tools, manufacture of tools, metallurgical flux, jewelry, to ignite fire, used in flintlock firearms.