Having diamonds only shows integrity (7)
I believe the answer is:
justice
'integrity' is the definition.
(thesaurus)
'having diamonds only' is the wordplay.
I cannot quite understand how this works, but
'diamonds' could be 'ice' (slang term for diamonds) and 'ice' is present in the answer.
'only' could be 'just' (synonyms) and 'just' is located in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
'shows' acts as a link.
Can you help me to learn more?
(Other definitions for justice that I've seen before include "Courts' function" , "Equity" , "right outcome" , "Rightness" , "Fairness, legitimacy" .)