Volcanic glass occcurs where magma cools so rapidly that crystals are unable to form. Like normal glass it is halfway between a solid and a gas but not a liquid fluid. It will shatter,break, have conchoidal fracture and produce sharp edges.
- Obsidian is a rhyolitic glass which appears black, formed when rhyolitic lava cools rapidly
- Pumice is considered glass as it has no crystal structure
- Peles hair : thin strands of glass
- Peles tears droplet of glass
- Polagonite basalitc glass with a low silica content.