Know all about Greywacke and Foidolite properties here. All properties of rocks are important as they define the type of rock and its application. Greywacke belongs to Sedimentary Rocks while Foidolite belongs to Igneous Rocks.Texture of Greywacke is Clastic whereas that of Foidolite is Earthy. Greywacke appears Dull and Foidolite appears Dull. The luster of Greywacke is dull while that of Foidolite is subvitreous to dull. Greywacke and Foidolite 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 Foidolite are cemetery markers, commemorative tablets, creating artwork.