Appealing for surface material in silver (6)
I believe the answer is:
asking
'appealing' is the definition.
(I've seen this before)
'surface material in silver' is the wordplay.
I cannot quite see how this works, but
'surface' could be 'skin' (skin is a kind of surface) and 'skin' is found in the answer.
'material' could be 'ag' (Ag is an example) and 'ag' is present in the leftover letters.
This accounts for all the letters.
This explanation may well be incorrect...
'for' is the link.
Can you help me to learn more?
(Other definitions for asking that I've seen before include "Making enquiries" , "Enquiring" , "Questioning" , "being inquisitive" , "For the ___; freely available" .)