LIFE LOCKED INSIDE A RUBY
Traces of ancient life have been found inside a 2.5-billion-year-old ruby from Greenland. The planet’s oldest rubies, gemstones made up of a transparent red mineral called corundum, are found in Greenland. While searching for rubies in the North Atlantic Craton, researchers discovered a hidden surprise in one of them: graphite, a pure form of carbon, which may be the remains of ancient microbial life.
“The graphite inside this ruby is really unique,” said Chris Yakymchuk, a professor at the University of Waterloo in Ontario. “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 analysed the ratio of different isotopes of carbon. More than 98 per cent of the carbon on Earth has a mass of 12 atomic mass units, but some carbon atoms are heavier, with a mass of 13 or 14 atomic mass units.
“Living matter preferentially consists of the lighter carbon atoms because they take less energy to incorporate into cells,” Yakymchuk said. “Based on the increased amount of carbon-12, we concluded that the carbon atoms were once ancient life, most likely dead microorganisms such as cyanobacteria.” At the time this bacteria likely lived, the planet didn’t have much oxygen, an indispensable element for complex life, so the only life that could eke out an existence were teeny microbes and algae films. Cyanobacteria are thought to be some of the first life on Earth.