Know all about Greywacke and Skarn properties here. All properties of rocks are important as they define the type of rock and its application. Greywacke belongs to Sedimentary Rocks while Skarn belongs to Metamorphic Rocks.Texture of Greywacke is Clastic whereas that of Skarn is Earthy, Mud-rich, Rough. Greywacke appears Dull and Skarn appears Dull. The luster of Greywacke is dull while that of Skarn is waxy and dull. Greywacke and Skarn 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 Skarn are creating artwork, gemstone, jewelry, metallurgical flux, source of magnesia (mgo).