White stone in altar base cracked (9)
I believe the answer is:
'white stone' is the definition.
(I've seen this before)
'altar base cracked' is the wordplay.
'cracked' is an anagram indicator.
'altarbase' is an anagram of 'ALABASTER'.
'in' is the link.
(Other definitions for alabaster that I've seen before include "Translucent white gypsum as found carved into ornaments" , "White mineral used for carving" , "Sculptors work with this" , "Altar base (anagr.)" , "Carved form of gypsum" .)