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