fulgurite
/ˈfʌlɡjəˌraɪt/
noun
- A tube or crust of glassy material formed when lightning strikes sand, rock, or soil, melting it.
- The hiker found a rare fulgurite in the desert after a thunderstorm.
- The museum displayed a beautiful fulgurite that looked like a twisted glass root.
- Scientists study fulgurites to learn about the power of lightning strikes.