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