The value of gold is the value that the market sets it as. It's not an artificial number at all. It's what people are actually paying for gold by the ounce. In times of great instability or uncertainty, gold's value increases significantly, because even if the government collapses and all currencies implode, gold will still be there, the idea being that the gold standard could be set, no matter what happened to the dollar/euro/pound/lira/whatever. So the more worried people are about the future, the more they're willing to pay for a currency that will still be valuable whatever may happen in the future. In 2008, even when the stock market plummeted, the value of gold rose sharply, steadily, something like tripling in value between 2008 and 2012. I'm sure everyone remembers that in early 2008, there was a very real fear that we were headed for another Great Depression.
Oh, also, random fact. There are 12 ounces in a pound of gold, not 16. So an ounce of gold weighs more than an ounce of feathers, though a pound of each weighs the same. (You can use that as a double trick question.)