Researchers from the University of Waterloo led by Chris Yakymchuk, professor of Earth and Environmental Sciences at Waterloo discovered carbon residue proving ancient life encased in a 2.5 billion-year-old ruby. “The graphite inside this ruby is really unique. It’s the first time we’ve seen evidence of ancient life in ruby-bearing rocks,” says Yakymchuk. “Based on the increased amount of carbon-12 in this graphite, we concluded that the carbon atoms were once ancient life, most likely dead microorganisms such as cyanobacteria,” he added. The graphite changed the chemistry of the surrounding rocks to create favorable conditions for ruby growth. It turns out that life may have been the secret ingredient for the ruby formation.The researchers studied rubies from the North Atlantic Craton of southern Greenland, where the oldest ruby deposits in the world are.
Rubies are a variety of the mineral corundum – a crystalline form of aluminum oxide. It forms under intense heat and pressure at Earth’s tectonic boundaries, where tectonic subduction and collision create the necessary environment. Yakymchuk and his team were seeking to better understand corundum formation processes. This graphite-containing ruby is hardly the oldest evidence of life found so far. Yakymchuk’s team published their finding in the peer-reviewed journal Ore Geology Reviews.