a dark volcanic glass formed by very rapid solidification of lava
Also called: Iceland agate
WordReference Random House Learner's Dictionary of American English © 2025
ob•sid•i•an /əbˈsɪdiən/USA pronunciation
n. [uncountable]
WordReference Random House Unabridged Dictionary of American English © 2025- Rocksa hard, dark, glasslike substance formed when volcanic eruptions cool.
ob•sid•i•an
(əb sid′ē ən),USA pronunciation n.
- Rocksa volcanic glass similar in composition to granite, usually dark but transparent in thin pieces, and having a good conchoidal fracture.
- Latin; see -an
- Latin Obsidiānus, printer's error for Obsiānus pertaining to Obsius, the discoverer (according to Pliny) of a similar mineral in Ethiopia; replacing Middle English obsianus
- 1350–1400
Collins Concise English Dictionary © HarperCollins Publishers::
'obsidian' also found in these entries (note: many are not synonyms or translations):
Iceland agate
- glass
- obsidian dating
- perlite
- spherulite
- trichite
- volcanic glass
- Çatalhüyük