Know all about Greywacke and Flint properties here. All properties of rocks are important as they define the type of rock and its application. Greywacke and Flint belong to Sedimentary Rocks.Texture of Greywacke is Clastic whereas that of Flint is Banded, Rough. Greywacke appears Dull and Flint appears Glassy or Pearly. The luster of Greywacke is dull while that of Flint is vitreous. Greywacke and Flint are available in beige, black, brown, colourless, cream, dark brown, green, grey, light green, light to dark grey, pink, red, white, yellow colors. The commercial uses of Greywacke are as armour rock for sea walls, petroleum reservoirs, sea defence, tombstones 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.