Two moments of reading stand out from my research, pivotal moments that confirmed the notion that if rocks are not alive in the conventional sense, they’re not dead either—in technical terms, that the lithosphere is as much a part of the ecosphere as the biosphere. One sentence came in a book by the eminent geologist Marcia Bjornerud: “more than 40 percent of all mineral species on Earth are in some sense biogenic”—that is, they are the result of organic activity. Chalk and limestone and cherts are made up of plankton shells, oxygenating microbes “grow” iron, coal consists of decomposed plant matter.
The second was a passage in Mircea Eliade’s ethnographic study of early metallurgy: “the imaginary world … came into being with the discovery of metals.” He went on to suggest that “metals opened up a new mythological and religious universe.” A bold claim that thrilled me and aroused my skepticism at the same time. In a sense, my book—Under a Metal Sky—is an attempt to prove Eliade’s point. He also brought into sharp focus a moment in pre-history, that primitive experiment, when a piece of dull stone was placed in a fire and a shiny liquid was seen to ooze from it.
Out of dead rock came something transformative; hardened, that liquid transformed lives in a dozen different ways. It also altered forever our relationship to the planet.