A haematite filament enveloped by a fine irregular layer of nanoscopic haematite from vent deposits in the Nuvvuagittuq Supracrustal Belt in Québec, Canada is pictured in this undated handout photo obtained by Reuters March 1, 2017. These filaments of iron, about half the size of a human hair, were made by primitive microbes involved in the carbon and iron cycles. (Photo/Agencies)
