Major Gold Miners' AISC, page-7

Yes gold is used, and like copper and lead, all that is mined can be re-used. The only metals that immediately come to mind that are really completely lost are uranium and zinc (because it is spread so thinly).

AISC puts a floor in. 2014 will be peak production for a long while I think. Discovery costs on new gold as a ratio of gold price now are greater than ever before - off the chart in fact. It is cheaper to buy out your competitors ounces than explore for your own if you want to add to your inventory. In the late 90's early 2000's the producers protected themselves by hedging. So for accounting profitability the measure was forward sale price vs AISC, independent of POG. But this downturn they aren't hedging.

Now that the cost cutting, high-grading, and max-throughput cycles are well over, we are into the closure cycle. This puts a floor in price. The majors will not get through quarter after quarter doing cap raises to survive.