Rink surface (3)
I believe the answer is:
ice
'rink surface' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ice that I've seen before include "Glaciate" , "Frozen water - diamonds" , "If it's thin, skating on it can be dangerous" , "such an age" , "Diamonds, colloquially" .)