noun / adjective
obsidian
ub-SID-ee-un/əbˈsɪdiən/
Dark volcanic glass formed when lava cools rapidly.
The obsidian has sharp, glassy edges along its curved fracture.
Etymology
The name means “of Obsius,” identifying the rock with a person rather than describing its glassy texture. Pliny alleged that this Roman had found the stone in Ethiopia.
In context
This is sometimes called dragonglass but its proper name is obsidian or volcanic glass. It cooled very quickly, there are no crystals inside here.
More examples
- The sharp edge of the obsidian blade cuts through leather.
- A piece of obsidian shines like glass in the sunlight.
- The museum displays arrowheads made from obsidian.
Similar words
- volcanic glass
- A broader term covering obsidian and other naturally glassy volcanic materials.