Properties of Breccia and Gneiss play an important role in determining the type of rock. Along with Breccia vs Gneiss properties, get to know more about Breccia Definition and Gneiss 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 Breccia and Gneiss.