A Lodestone for My Journey

Helmet on. Belt w eighed down with emergenc y oxygen pack. The steel doors shut, a bell sounds from far below, and the cage descends. Very slowly at first. Then suddenly faster. Within fifteen seconds we are traveling at nearly 40 miles an hour down a shaf t into the earth. The cage rocks slightly but keeps on descending longer than you can, believe. Somewhere in the dar k beside us, another c age shoots past in the opposite direction, hurtling to the surface and full of rock. Soon we have gone down deeper than the Grand Cany It gets warmer. Every 100 yards—every six seconds—the temperature rises by a degree. Down at the bottom of the shaft, almost three miles below the earth’s surface and deeper than the ocean floor, the rocks are at more than 120°F. The muggy air is at twice the pr ssure of the sure face air. And radioactive. Scientists have found microbes down here in the dar k whose onl y source of energ y is the radiation from the earth’s core. Gradually the lif t slows and halts with a r eassuring c lunk. The doors open and w step out into the earh’s crust. I switch on the lamp et on my helmet and peer around at the rocks. Three billion years ago,
they were the grav elly deposits of a r iver delta. All sor ts of metals were washed down from surrounding mountains that have long since
eroded away. And some of those metals accum ulated in the grav el beds. One metal in particular accumulated here. And, as a result, this tunnel leads through the heart of what is by a huge margin the richest goldfield on Earth. The West Witwatersrand goldfield in South Africa is also the deepest workplace on the planet.Welcome, says myguide, to Driefontein mine. I am here to find out wher e the gold in my w edding ring came from. It is the one thing I neer take on; the one thing that c me with me every step of the way on my journeys to find my global footprint. As I step out into the Driefontein tunnel, I look again at it. My wife and I bought our bands of gold bac in the summer of 1979,in a jew keler’s shop on the S trand in central L ondon. We still hav e the receipts. They cost £50 each. Where did those r ings come f rom? In theory, every piece of gold can be traced back to an individual mine. The gold has its own chemical fingerprint because of the impurities that come with it as it leav s the earth. But in practice, gold in jewelry e is usuall y c ast f rom a range of sour ces, and my r ing defies finger printing.