Fine stone (3)
I believe the answer is:
gem
'fine stone' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for gem that I've seen before include "Diamond, ruby, or emerald" , "Setter might bed this" , "Half of 7 [SIGN OF THE ZODIAC]" , "Treasured person" , "Valued person; jewel" .)