Diamonds used in specific earrings (3)
I believe the answer is:
ice
'diamonds' is the definition.
(I've seen this before)
'in specific earrings' is the wordplay.
'in' says the answer is hidden in the clue.
'ICE' is hidden within 'specific earrings'.
'used' is the link.
(Other definitions for ice that I've seen before include "If it's thin, skating on it can be dangerous" , "Block" , "A state of water" , "Cooler" , "Skating surface" .)