It's the cr?me de la cr?me from one of The Stones (5)
I believe the answer is:
jewel
'of the stones' is the definition.
The definition suggests a singular noun which matches the answer.
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for jewel that I've seen before include "(Semi) precious stone" , "Precious stone or mineral" , "The - That Was Ours (Dexter)" , "Gem" , "Gemstone" .)