Gold costs were about $317 per troy ounce in 2007, but these can vary widely depending on mining type and ore quality; global mine production amounted to 2,471.1 tonnes. After initial production, gold is often subsequently refined industrially by the Wohlwill process which is based on electrolysis or by the Miller process, that is chlorination in the melt. The Wohlwill process results in higher purity, but is more complex and is only applied in small-scale installations. Other methods of assaying and purifying smaller amounts of gold include parting and inquartation as well as cupellation, or refining methods based on the dissolution
Commodity value Commodity value In the field of economics, the commodity value of a good is its free market intrinsic value under optimal use conditions. In a free market, the commodity value of a good will be reflected by its price. For example, if an acre of land can yield a net of 100 dollars loss by lying fallow, 50 dollars gain by being planted with corn, and 100 dollars gain by being planted with wheat, then that acre's commodity value is 100 dollars; the farmer is assumed to put his land to best use. The price of a commodity fluctuates around