Soaring diesel prices, driven by disruption to shipments through the Strait of Hormuz, are working through mining cost bases, and the October 23 Mining.com analysis of company results shows the burden falling unevenly. Antofagasta raised its full year copper cash cost guidance by almost 30 cents, to between 2.60 and 2.70 dollars a pound, citing higher diesel prices. Capstone Copper reported second quarter C1 cash costs up 15 percent year on year to 2.82 dollars a pound, with costs at its Mantos Blancos mine up 88 percent to 3.93 dollars, including about 34 cents a pound from higher mining costs, mainly diesel.
Byproducts and smelters are the hedges that work. At Capstone’s Mantoverde mine, stronger gold byproducts cut C1 costs by 16 percent despite diesel adding 23 cents a pound. Ivanhoe Mines absorbed an 18 cent a pound diesel cost increase at Kamoa-Kakula and still generated 385 million dollars of second quarter earnings before interest, tax, depreciation and amortisation, helped by copper prices and by sulphuric acid sales covering its smelter’s operating costs.
Gold producers have had the largest cushion. Barrick’s gold production cost rose 17 percent between 2025 and 2026 in part on fuel, yet attributable adjusted earnings rose 51 percent to 2.55 billion dollars in the second quarter. Kinross reported production cost of sales up 25 percent to 1,352 dollars an ounce while its margin rose 42 percent to 3,131 dollars. A World Gold Council report on the first quarter found diesel prices up 54 percent in the United States and almost doubled in Australia, where some junior operations suspended activity on fuel constraints. Newmont has estimated that every 10 dollars a barrel on oil adds 110 million dollars, or 21 dollars an ounce, to its production costs.
TD Cowen warned in March that surging energy prices threatened margin expansion, estimating a 15 percent rise in all in sustaining costs and 22 percent higher all in costs. The test arrives if metal prices retreat while fuel stays high. In the latest market tables copper rose 1.78 percent to 6.48 dollars a pound but gold fell 1.29 percent to 4,007.90 dollars and silver fell 1.92 percent, with gold miners down 8.56 percent on the week. Third quarter results will show whether the cushion held.