Gold mining is estimated to create 40,000 pounds (18,000 kg) of waste to yield enough gold for one 18-karat gold ring. When gold is mined from the ground, it typically is mixed with other rock that needs to be separated in order to process the gold. This excess rock is known as waste rock. Waste rock generally has no other use and is disposed of. Some mines treat waste rock with toxic substances, such as cyanide, to help separate it from the gold. Many countries have specific laws about how waste rock must be handled, to prevent contaminating water supplies, for example.
More about gold mining:
- A total of 182,000 tons (165 million kg) of cyanide each year are estimated to be used by gold mines throughout the world.
- The waste generated from producing the gold needed for one 18-karat gold ring would weigh about as much as 10 average-size cars.
- Waste rock dumped by the mining industry in the United States is estimated by the US Environmental Protection Agency to contain hundreds of millions of pounds of toxic substances, and some estimates are as high as hundreds of billions of pounds.