Wealthwire list of some obscure & not so obscure facts about the yellow shiny stuff - I like no.45 particularly 
http://www.wealthwire.com/news/metals/2999
http://www.wealthwire.com/news/metals/2999
geewiz said:"6. There is an estimated total of 10 billion tons of gold in the world's oceans. That is 25 tons of gold for every cubic mile of seawater."
I did not know this fact, how interesting