Physical properties of rocks are used to identify the type of rocks and to discover more about them. There are various physical properties of Obsidian like Hardness, Grain Size, Fracture, Streak, Porosity, Luster, Strength etc which defines it. The physical properties of Obsidian rock are vital in determining its Obsidian Texture and Obsidian Uses.
The physical properties of Obsidian depend on its formation. Physical properties of rocks play an important role in determining its applications in various fields. Rocks are rated on the on the Moh's Hardness Scale which rates the rocks on the scale from 1 to 10. Rocks with hardness 1-3 are soft rocks from 3-6 are medium hardness rocks and 6-10 are hard rocks. The hardness of Obsidian is 5-5.5 whereas its compressive strength is 0.15 N/mm2. Streak is the color of rock when it is crushed or powdered. The streak of Obsidian is white whereas its fracture is conchoidal. Luster of Obsidian is the interaction of light with the surface of Obsidian. Luster of Obsidian is vitreous. Obsidian cleavage is non-existent. The specific gravity of Obsidian is 2.6-2.7. Obsidian is translucent in nature whereas its toughness is not available. You can also know all the list of rocks in Opaque Rocks, Translucent Rocks and Transparent Rocks.