Related Clues:
- With 59 Down, ''pumice-powered'' product
- Lava before we can see it
- Volcano's spew
- Source of volcanic glass
- Stuff from volcanoes
- Red-hot flow
- Hot flowing rock
- Lava, before its exit
- What obsidian forms from
- Stuff of the volcano
- Volcanologist's subject
- Underground rock
- Glowing rock
- Molten material's reduced periodical state
- Pahoehoe or a'a, e.g