INDIA’S “sand mafia” is doing a roaring trade. The Times of India estimates that the illicit market for sand is worth around 150bn rupees ($ 2.3bn) a year; at one site in Tamil Nadu alone, 50,000 lorryloads are mined every day and smuggled to nearby states. Gangs around the country frequently turn to violence as they vie to continue cashing in on a building boom.
Much of the modern global economy depends on sand. Most of it pours into the construction industry, where it is used to make concrete and asphalt. A smaller quantity of fine-grade sand is used to produce glass and electronics, and, particularly in America, to extract oil from shale in the fracking industry. No wonder, then, that sand and gravel are the most extracted materials in the world. A 2014 report by the United Nations Environment Programme (UNEP) estimates they account for up to 85% by weight of everything mined globally each year.
With house-building in the West yet to recover fully from the 2007-08 crisis, Asia has been, by far, the main source of demand. Figures from the Freedonia Group, a market-research firm, suggest that, of the 13.7bn tonnes of sand mined…