I've rediscovered my stash bought mostly in the '90s including large amulet cases with dangles, metal drops, chains , lapis slabs, glass and coral bits set in shallow mounts with what looks like bitumen, some enamel etc. and if I ever want to show them off or do business with them then they must look glowing not drab, whether the metals themselves are silver, tin, nickel, brass, copper, iron, gilded, or a mix..
Vinegar? Salt? Lemon juice? silver dip? detergent? woolwash? ultrasonic? elbowgrease?
All suggestions welcome!