Green stone (4)
'green stone' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for jade that I've seen before include "Overworked horse; stone" , "weary" , "horse not in prime condition" , "Green stone; hack" , "disreputable woman" .)
'green stone' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for emerald that I've seen before include "On of the Greens" , "Small size of type, in printing" , "Precious gemstone" , "Mere lad (anag.)" , "Bright green colour" .)