Know all about Greywacke and Tephrite properties here. All properties of rocks are important as they define the type of rock and its application. Greywacke belongs to Sedimentary Rocks while Tephrite belongs to Igneous Rocks.Texture of Greywacke is Clastic whereas that of Tephrite is Aphanitic to Porphyritic. Greywacke appears Dull and Tephrite appears Vesicular. The luster of Greywacke is dull while that of Tephrite is subvitreous to dull. Greywacke and Tephrite 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 Tephrite are production of lime, soil conditioner.