Gold Part 3
Gold – Part 3
Written for the KidsKnowIt Network by:
Surprisingly though, with as much gold that was found and used in the ancient world, 75% of the gold that has been mined has been mined after 1910 CE. In 2009, people calculated that all of the gold ever mined was about 165,000 metric tons. If you could melt down all that gold and put it on one place it would make a cube measuring 20.28 meters (67 feet) on each side. That’s a whole lot of gold.
South Africa and China are the biggest producers of gold in the world; each country producing almost 2000 metric tons (1000kg/metric ton) of gold per year. The states of South Dakota and Nevada supply most of the gold used in the United States. Nevada alone supplies about 79% of the gold used in the United States.
Most of the gold mined anymore isn’t in nuggets or veins, it is found in rocks but in such small concentrations that the gold can’t be seen. The gold has to be chemically pulled from the rock and concentrated. There are some geologists that think there are many deposits of this kind of gold overlooked by miners in the past because they couldn’t see the gold in the rock in front of them. Places like the Carlin Trend geologic formation in Nevada have a lot of these nearly invisible gold deposits.
A lot of the gold we get comes from mines like the Bingham Canyon Mine in Utah. The Bingham Canyon Mine is the largest open pit mine in the United States. At this mine they dig for copper. While mining and extracting copper, they also extract a lot of gold from the rocks they crush and pulverize. In this case, gold is a side product of the mine. Many of the mines in Nevada are also open pit mines and they use the same method; they dig a really big hole in the ground, find the rocks they want, crush them up, and chemically extract the gold right from the powdered rock.