Capital is new with fool's gold (6)
I believe the answer is:
nassau
'capital' is the definition.
(Nassau is an example)
'new with fool's gold' is the wordplay.
'new' becomes 'n'.
'with' is a charade indicator (letters next to each other).
'fool's' becomes 'ass' (ass is a kind of fool**).
'gold' becomes 'au' (Au is the chemical symbol for gold).
'n'+'ass'+'au'='NASSAU'
'is' is the link.
(Other definitions for nassau that I've seen before include "Bahamas cap." , "city" , "Bahamian capital" , "Caribbean resort" , "Port of the Bahamas" .)