Nice piece, at first glance I'd say no to clean, at second glance I'd say maybe because the stones are cut in a ruff mannor unlike modern day stones....maybe
at third glance...
also working your way in from any end point you go past the emerald setting to a setting holding what appear to be diamonds to either side of this setting are gold rods or bars that look the way high iron content gold looks after being in the water and getting a good cleaning....however, also the gold on said rods is also possibly electroplated pieces that have delaminated from the base metal...both scenarios look similar.................just my opinion............................Limo Bob
at forth and final glance ...i noticed an emerald off the center diamond (bottom left one)...it is broken and missing a piece this could not happen to imitation stone, but to a natural emerald this is common....so I'm going with real....old....possibly from water if so must have gotten there by a ship of some sort......................................Limo Bob