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