Material may be mined (5)

I believe the answer is:

denim

'material' is the definition.
(type of fabric)

'may be mined' is the wordplay.
'may be' indicates an anagram.
'mined' is an anagram of 'DENIM'.

(Other definitions for denim that I've seen before include "Coarse durable twill-weave cotton fabric" , "Hard-wearing blue fabric" , "Cotton twill fabric" , "dark blue material" , "Hard-wearing cotton fabric" .)

I've seen this clue in the Evening Standard.

Want a hint initially instead of a full solution? Install my app