Know all about Greywacke and Nepheline Syenite properties here. All properties of rocks are important as they define the type of rock and its application. Greywacke belongs to Sedimentary Rocks while Nepheline Syenite belongs to Igneous Rocks.Texture of Greywacke is Clastic whereas that of Nepheline Syenite is Granular. Greywacke appears Dull and Nepheline Syenite appears Banded and Foilated. The luster of Greywacke is dull while that of Nepheline Syenite is greasy to dull. Greywacke is available in beige, black, brown, colourless, cream, dark brown, green, grey, light green, light to dark grey, pink, red, white, yellow colors whereas Nepheline Syenite is available in brown, buff, cream, green, grey, pink, white colors. The commercial uses of Greywacke are as armour rock for sea walls, petroleum reservoirs, sea defence, tombstones and that of Nepheline Syenite are cemetery markers, creating artwork.