A term that has suddenly come to the fore in recent months is "urban mining," the idea that there are precious metals in the everyday objects that surround us that can be recycled. The most prominent example is old cell phones, which contain both iridium and gold. There's not enough in one to make its owner rich, but, for instance, a ton of ore from a gold mine typically gives up only 5 grams of real gold, while a ton of discarded cell phones could represent as much as 150 grams of gold.
Japan is generally acknowledged to have the largest potential urban mine of any country in the world. It is believed the general public possesses 6,800 tons of gold, mostly in the form of jewelry and accessories, but also in ingot and bar forms, not to mention "hidden" gold in electronics devices. (Many Japanese keep their old cell phones because they want to hold onto the data they contain.) That's the equivalent of 16 percent of what is estimated to be all the "uncovered" gold in the ground worldwide. Silver is even more: 60,000 tons, or 22 percent of the amount still buried.