Obsidian is perhaps best known in its role as the dark black blade atop ancient spears ... rainbow obsidian is both rock and glass. However, this isn’t the same kind of glass that’s used ...

Expansive lava flows in the Sáttítla Highlands was captured by satellites ahead of the recent designation of the area as a national monument.

The Kilauea volcano on Hawaii’s Big Island sprang to life yet again this week with a Tuesday morning eruption that shot lava more than 300 feet in the air. The latest incident started at about 10:16 a ...

reminiscent of volcanically created obsidian glass on Earth," Bolton said. Rugged islands of rock crowd the lava lake's interior. "There is amazing detail showing these crazy islands embedded in ...