Know all about Greywacke and Chert properties here. All properties of rocks are important as they define the type of rock and its application. Greywacke and Chert belong to Sedimentary Rocks.Texture of Greywacke is Clastic whereas that of Chert is Banded, Rough. Greywacke appears Dull and Chert appears Glassy or Pearly. The luster of Greywacke is dull while that of Chert is waxy and dull. Greywacke and Chert 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 Chert are creating artwork, gemstone, in fire-starting tools, jewelry, to ignite fire, used in flintlock firearms.