Its metallic qualities are not unique (5)
I believe the answer is:
alloy
'its metallic qualities' is the definition.
I can't judge whether this defines the answer.
'not unique' is the wordplay.
I cannot quite see how this works, but
'not' could be 'o' (I've seen this in other clues) and 'o' is found within the answer.
The remaining letters 'ally' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'are' acts as a link.
Can you help me to learn more?
(Other definitions for alloy that I've seen before include "Mixed metal" , "A mix of two or more metals" , "Metal mixture" , "Mixture of two or more metallic elements" , "Eg, pewter or brass" .)