Sorowako, on the Indonesian island of Sulawesi, is the site of one of the largest nickel mines on earth. Nickel is an invisible part of many everyday objects: it disappears into stainless steel, the heating elements of domestic appliances and the electrodes of rechargeable batteries.
It was formed here more than two million years ago, when the hills that surround Sorowako began to emerge along an active fault. Laterites – iron oxide and nickel-rich soils – developed through the relentless erosion of tropical rain. When I rode my scooter into the hills, the ground duly changed colour, becoming red with blood-orange streaks.