The most common and most likely answer to this crossword clue is the 8 letter word OBSIDIAN
I've seen this crossword clue in The Times
O
B
S
I
D
I
A
N
More clues leading to the result OBSIDIAN
- Help is turning up after former schoolmate gets stuck on Northern rock
- Rock band so bad I must repeatedly interrupt
- Vicious perhaps, Scotsman chasing alumnus produces glass
- Rock band I love is playing
- Old boy joining Vicious and Dury in a sort of rock
- Volcanic glass is picked up by investigator in Scottish town
- Glass is raised by detective in Scottish town
- Some foreign aid is bought back as result of volcanic activity
- Vicious Scotsman pursuing alumnus produces glass
- On first of burglaries, help is given about breaking glass
Buddy explains!
The straight part
We know that "rock" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case rock = obsidian.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does OBSIDIAN mean?
OBSIDIAN noun- A type of black glass produced by volcanoes.
- Black