In a recent interview, Summer Sanders — the quadruple Olympic medalist — explained that photographers always ask her to bite her medals – typically at the conclusion of photo shoot sessions on Olympic medal podiums.
This practice dates back to the tradition of biting metal to gauge whether it is pure gold. Tooth enamel is harder than gold (especially pure gold), so it is possible to leave marks on it with your teeth. Doing this enables you to determine whether the gold item has a gold exterior, with a different type of metal in the middle. If it does, then you can use your teeth to scrape off the gold exterior. Old fashioned gold coins were fairly thin, so you did not need to bite hard to find out whether it was pure gold.
Of course, Olympic athletes are not trying to bite their medals to check the metal’s authenticity. It simply makes for a more eye catching photo, compared to a shot of an athlete holding a medal up to his or her face.
Needless to say, the gold medals used at modern day Olympic games are not pure gold. This has been the case since 1912, although today’s medals do have a twenty-four carat gold plating. Instead, sterling silver is the main metal used to make the medals. However, if you did bite on an Olympic gold medal, you would make a mark on it. Tooth enamel is harder than sterling silver as well.