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