Carved gemstone (4)
I believe the answer is:
jade
'carved gemstone' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for jade that I've seen before include "Green gemstone" , "Greenish, semi-precious stone" , "Semiprecious stone - shade of green" , "Green stone; hack" , "Worn-out horse" .)