Material that's mined in a new way (5)
I believe the answer is:
denim
'material' is the definition.
(denim is a kind of material)
'mined in a new way' is the wordplay.
'in a new way' is an anagram indicator.
'mined' anagrammed gives 'DENIM'.
'that's' is the link.
(Other definitions for denim that I've seen before include "Hard-wearing cloth" , "Thick cotton cloth" , "Mined badly for a hard-wearing fabric" , "Tough cotton fabric" , "Coarse durable twill-weave cotton fabric" .)