Know all about Greywacke and Minette properties here. All properties of rocks are important as they define the type of rock and its application. Greywacke belongs to Sedimentary Rocks while Minette belongs to Igneous Rocks.Texture of Greywacke is Clastic whereas that of Minette is Porphyritic. Greywacke appears Dull and Minette appears Dull, Banded and Foilated. The luster of Greywacke is dull while that of Minette is subvitreous 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 Minette is available in black, bluish - grey, brown, dark greenish - grey, green, grey colors. The commercial uses of Greywacke are as armour rock for sea walls, petroleum reservoirs, sea defence, tombstones and that of Minette are an oil and gas reservoir, as a feed additive for livestock, gemstone, metallurgical flux, production of lime, soil conditioner, source of magnesia (mgo).