Stone used in fridge manufacture (3)
I believe the answer is:
gem
'stone' is the definition.
(thesaurus)
'in fridge manufacture' is the wordplay.
'in' indicates the answer is hidden within the clue.
'GEM' can be found hidden inside 'fridge manufacture'.
'used' is the link.
(Other definitions for gem that I've seen before include "A precious stone like a diamond or emerald etc" , "Precious or semi-precious stone" , "Pleasant and cheerful (from German)" , "A jewel of an Orangeman" , "Pearl" .)