Know all about Greywacke and Marl properties here. All properties of rocks are important as they define the type of rock and its application. Greywacke and Marl belong to Sedimentary Rocks.Texture of Greywacke is Clastic whereas that of Marl is Earthy. Greywacke appears Dull and Marl appears Rough and Dull. The luster of Greywacke and Marl is dull. Greywacke and Marl 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 Marl are creating artwork, soil conditioner.