Naturally Occurring Volcanic Glass
This page is the CodyCross answer for the clue below from Popcorn Time, Group 391, Puzzle 2 (Double Feature).
Question is: Naturally Occurring Volcanic Glass
and the answer is: OBSIDIAN
Word Meaning:
OBSIDIAN — (mineralogy) A type of naturally occurring black glass produced by volcanoes.
Definitions from Wiktionary.