It looks like copper Rose, and may be silver plated (probably epns). The weight is most likely a lead bung in the base to give it stability. Personally I wouldn't be tempted to polish it right up, I prefer a nice patina and polishing may make it look to harsh and 'new'. I'd rather just use a soft cloth and elbow grease to put some shine back into it, but if you are tempted to polish it, maybe start underneath on the inner rim and see what happens.