Mountain of metal and wood (6)
I believe the answer is:
alpine
'mountain' is the definition.
(I've seen this before)
'metal and wood' is the wordplay.
'metal' becomes 'al' (chemical symbol for aluminium).
'and' is a charade indicator (letters next to each other).
'wood' becomes 'pine' (pine is a kind of wood).
'al'+'pine'='ALPINE'
'of' is the link.
(Other definitions for alpine that I've seen before include "Native growing up in mountainous area" , "Relating to high mountains" , "from Germany, Austria etc" , "Plant of high mountains" , "To do with great European mountains" .)