Dark volcanic glass formed by very rapid solidification of lava

Let's find possible answers to "Dark volcanic glass formed by very rapid solidification of lava" crossword clue. First of all, we will look for a few extra hints for this entry: Dark volcanic glass formed by very rapid solidification of lava. Finally, we will solve this crossword puzzle clue and get the correct word. We have 1 possible solution for this clue in our database.