variolite
/ˈvɛriəˌlaɪt/
noun
- A type of volcanic rock that contains small, round, light-colored spots or spherules, often found in ancient lava flows.
- Geologists studied the variolite to understand the cooling history of the ancient lava flow.
- The hiker picked up a piece of variolite with its distinctive pale spots against the dark matrix.
- The museum displayed a polished slab of variolite, showing its beautiful orbicular texture.