Properties of Greywacke and Nepheline Syenite play an important role in determining the type of rock. Along with Greywacke vs Nepheline Syenite properties, get to know more about Greywacke Definition and Nepheline Syenite Definition. For the ease of understanding, the properties of rocks are divided into physical and thermal properties. Rocks have a variety of properties like hardness, color, specific gravity, fracture, cleavage, luster etc. Know all about physical and thermal properties of Greywacke and Nepheline Syenite.