2.5 billion-year-old Traces of Life Locked Inside Primeval Ruby

According to new research, traces of ancient life were found within a 2.5 billion-year-old Ruby from Greenland. Greenland is home to the world’s earliest rubies, gleaming red jewels formed of a translucent red mineral called corundum. A group of geologists hunting for rubies in southern Greenland’s North Atlantic Craton uncovered a secret surprise in one of them: graphite, a pure form of carbon that might represent the leftovers of ancient microbial life.

Chris Yakymchuk, a professor of Earth and Environmental Sciences at the University of Waterloo in Ontario, Canada said that the graphite inside this Ruby is really unique. “It’s the first time we’ve seen evidence of ancient life in Ruby-bearing rocks.”The team concluded the graphite came from an ancient life-form after they analyzed the ratio of different versions, or isotopes, of carbon in the graphite.

More than 98% of the carbon on the planet has a mass of 12 atomic mass units, but some carbon atoms are heavier, with a mass of 13 or 14 atomic mass units. Yakymchuk said that living matter preferentially consists of lighter carbon atoms because they take less energy to incorporate into cells. 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.

At the time this ancient bacteria likely lived, the planet did not have much oxygen an indispensable element for complex life so the only lives that could eke out an existence were teeny microbes and algae films. Cyanobacteria are thought to be some of the first life on Earth, and through billions of years of converting sunlight into chemical energy, they gradually produced the oxygen necessary for complex life to eventually evolve, Live Science previously reported.