http://bleacherreport.com/articles/2710760-over-100-2016-olympic-medals-returned-due-to-rust-black-spotshttp://www.independent.co.uk/sport/defective-olympic-medals-returned-rio-games-brazil-athletes-gold-silver-bronze-a7746056.htmlI'm still confused as to what materials they were. So normally there are three nominal classes of awards: gold, silver, and bronze.
Some "rusted," some showed black spots, some the "varnish" had been damaged.
"Rusted" implies iron material, "black spots" would imply maybe silver (which turns black on exposure to a sulfur-rich environment) and "varnish" implies that the Olympics people knew they were fragile one way or another.
Gold is pretty incorruptible unless the gold peels off the substrate in "gold-filled" trinkets.
Silver is pretty soft and might require some kind of protective coating, and there's the sulfur thing.
Bronze is pretty incorruptible as well. Bronze artifacts have fairly well survived for millennia under sea water, longer if just lying around.
Ferrous materials will rust, unless protective coatings like varnish are applied, or are galvanized or painted ("varnished.")
So exactly how were these things put together? I can see lead or its alloys being used in the gold medals for the weight.
It
almost seems ike it would have been cheaper in the long run to just make them of the nominal materials and be done with it with no bad publicity.