Cut through mass of stone and shell of concrete (6)
I believe the answer is:
pierce
'cut through' is the definition.
(synonyms)
'mass of stone and shell of concrete' is the wordplay.
'mass of stone' becomes 'pier' (I can't explain this - if you can you should believe this answer much more).
'and' is a charade indicator (letters next to each other).
'shell of' means to remove the middle letters.
'concrete' with its centre removed is 'ce'.
'pier'+'ce'='PIERCE'
Can you help me to learn more?
(Other definitions for pierce that I've seen before include "Break skin of" , "Riddle" , "Impale" , "Bore hole through, perhaps ear" , "Penetrate as with sharp object" .)