"Silver has intrinsic value because it is a commodity; it’s rare, and it exists regardless of the world around it. In this regard, silver is a safer investment than the S&P500 because it has real intrinsic value. An ounce of silver will exist regardless of the life of the S&P500 components."

http://www.ibtimes.com/articles/266253/20111213/silver-s-beta-irrelevant.htm