The ongoing London Olympics are currently the topic of global conversation. News reports of all kinds about the Olympic Games are coming to audiences worldwide, covering the athletes' performances, who are the champions and what are the stories behind their successes. However, there are some Olympic facts that these reports forget to mention.

Below follows the top 10 of rarely-known Olympic facts.

 Silver: Main content of gold medal

Silver: Main content of gold medal [bethune.net.cn]

Most people simply assume that the gold medal is entirely made out of pure gold. However, the truth is that there has been no pure gold medal since the 1912 Olympics. The main content of today's gold medal is silver, and only about 6 grams of gold are used used in each gold medal.