There are two main sources for gold: mining and scrap. As gold prices go up, gold recycling becomes more attractive. But different pieces of recycled gold vary in the amount of gold they actually contain. Gold can be mixed with other metals like copper, which is used in red gold, or mercury, which is used in dental gold.
Hardrock Mining: This is the process by which open, or underground mines, remove rock which contains gold ore. The ore can then be processed to remove the gold, traditionally using mercury (historically), and cyanide. This method has declined in recent years due to the costs and the environmental impact that the process of refining has.