We are raiding the Guardian Long Read archives to bring you some classic pieces from years past, with new introductions from the authors. This week, from 2019: Demand for ‘healing’ crystals is soaring – but many are mined in deadly conditions in one of the world’s poorest countries. And there is little evidence that this billion-dollar industry is cleaning up its act. By Tess McClure. Help support our independent journalism at theguardian.com/longreadpod