It's mined in foreign parts (3)
I believe the answer is:
ore
'it's mined' is the definition.
(I've seen this in another clue)
'in foreign parts' is the wordplay.
'in' says the answer is hidden in the clue.
'ORE' can be found hidden inside 'foreign parts'.
(Other definitions for ore that I've seen before include "Solid rock containing metal" , "Mineral containing valuable metal" , "Small coins" , "foreign money" , "It's mined for minerals" .)