Prop removed, pass on a stone (5)
I believe the answer is:
agate
'stone' is the definition.
(I know that agate is a type of calcedony)
'prop removed pass on a' is the wordplay.
I cannot really understand how this works, but
'on' could be 'at' (I've seen this in other clues) and 'at' is found in the answer.
'a' is found in the answer.
The remaining letters 'ge' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for agate that I've seen before include "Ornamental form of quartz" , "Onyx" , "marble" , "Semi-precious stone" , "Hard stone with concentric bands of colour" .)