Stone from a ring, replaced before the centre's fallen out (7)
I believe the answer is:
granite
'stone' is the definition.
(I've seen this before)
'a ring replaced before the centre's fallen out' is the wordplay.
'replaced' is an anagram indicator.
'before' means one lot of letters go next to another.
'centre's fallen out' says to hollow out the word (remove centre letters).
'the' with its centre removed is 'te'.
'a'+'ring'='aring'
'aring' anagrammed gives 'grani'.
'grani'+'te'='GRANITE'
'from' acts as a link.
(Other definitions for granite that I've seen before include "Tearing (anag.)" , "Igneous rock, generally composed of feldspar and mica and quartz" , "Get rain (anag) - rock" , "Constituent in Dartmoor" , "Showing great resolution" .)