Petty quarrel with a New York jeweller (7)
I believe the answer is:
tiffany
'jeweller' is the definition.
(Tiffany and Co. is an American jewelry company)
'petty quarrel with a new york' is the wordplay.
'petty quarrel' becomes 'tiff' (I've seen this in another clue).
'with' means one lot of letters go next to another.
'new york' becomes 'ny'.
'tiff'+'a'+'ny'='TIFFANY'
(Other definitions for tiffany that I've seen before include "fine fabric" , "gauzy fabric" , "like a sort of glass" , "Girl's name - New York jeweller" , "US glass designer" .)