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