Know all about Chert and Greywacke properties here. All properties of rocks are important as they define the type of rock and its application. Chert and Greywacke belong to Sedimentary Rocks.Texture of Chert is Banded, Rough whereas that of Greywacke is Clastic. Chert appears Glassy or Pearly and Greywacke appears Dull. The luster of Chert is waxy and dull while that of Greywacke is dull. Chert is available in black, brown, green, grey, red, white colors whereas Greywacke is 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 Chert are creating artwork, gemstone, in fire-starting tools, jewelry, to ignite fire, used in flintlock firearms and that of Greywacke are as armour rock for sea walls, petroleum reservoirs, sea defence, tombstones.