Stone tearing rocks (7)
I believe the answer is:
granite
'stone' is the definition.
(granite is a kind of stone)
'tearing rocks' is the wordplay.
'rocks' is an anagram indicator.
'tearing' with letters rearranged gives 'GRANITE'.
(Other definitions for granite that I've seen before include "Get rain (anag) - rock" , "Coarse-grained igneous rock" , "A very hard rock from Tangier" , "Constituent in Dartmoor" , "determination" .)