News History of Olympic Gold By ETonline Staff 9:42 PM PDT, August 3, 2012 ET was with the U.S. Olympians in London, celebrating the hard-working athletes who all had one thing in mind -- bringing home the gold.PICS: Shirtless Hunks of the Olympics A few facts about the coveted medals:1. The gold medals are actually 92.5 percent silver with a gold plating.2. The last time they were made entirely of gold was 1912.3. They are 3mm thick and 60mm in diameter.4. They're valued at around $706. Watch the video to see Christina McLarty's tour of Goldsmith's Hall, as she gets a rare look at extraordinary gold pieces spanning 4500 years.