Written in stone

Abstract

The latest evidence that people are refashioning Earth is written not in the sky, where carbon dioxide levels are rising, nor in the acidifying ocean, but in stone. Geologists have identified about 200 minerals that formed due to the hustle and bustle of human activity. Many of these unintentionally formed minerals appeared on Earth during the past two centuries, a blip in the timescale of thousands to millions of years that geologists typically work with. “It is happening in a geologic instant, in the blink of an eye,” says Robert M. Hazen from the Geophysical Laboratory at the Carnegie Institution for Science. Hazen led a research team that cataloged the human-influenced minerals last month (Am. Mineral. 2017, DOI: 10.2138/am-2017-5875). The uptick in mineral diversity is more than just an expanded checklist for rock hounds. To Hazen and colleagues, it grants further credence to the notion that humans have driven Earth