Building journalist provided rocks (7)
I believe the answer is:
edifice
'building' is the definition.
(I know that building can be written as edifice)
'journalist provided rocks' is the wordplay.
'journalist' becomes 'ed' (short for editor).
'provided' becomes 'if' (eg 'provided it's sunny' means 'if it's sunny').
'rocks' becomes 'ice' (both can informally mean diamonds).
'ed'+'if'+'ice'='EDIFICE'
(Other definitions for edifice that I've seen before include "Large structure" , "impressive pile!" , "Grand building" , "Monument" , "Fine building" .)