I'm with D&b on the cloisonne opinion .
Perhaps your item was one that was 'remanufactured' into a lamp .
I've seen many nice asian champleve & cloisonne vases/urns/ginger-jars 're-purposed' into lamp items , which generally reduces their value .
A likely spot to look for artist sigs & etc. is the bottom of the base of the jar (requires disassembly of your lamp) .
Nice motif & item , tara1245 .