Residue of ancient life found on 2.5 billion-year-old ruby
The ruby was formed when life on Earth was far less diverse than it is today.
Scientists at the University of Waterloo have found graphite - a crucial component for organic life - on a 2.5 billion-year-old ruby discovered in Greenland.
While not all carbon is indicative of life, the type found in the ruby contains isotopes indicating its atoms were once part of a living organism.
More than 98 per cent of all carbon atoms have a mass of 12 atomic mass units, the researchers said in a statement, but some carbon atoms have a heavier 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,” Chris Yakymchuk, professor of Earth and Environmental Sciences at Waterloo and lead researcher on the study involving the ruby, said in the statement.
“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.”
When the ruby first formed, life wasn't as diverse on Earth as it is today, limited to microorganisms and algae.
Upon analyzing the gem, Yakymchuk’s team found that this graphite contained in the ruby isn't just a link to ancient life: its presence may have been necessary for the ruby to form in the first place.
"The graphite changed the chemistry of the surrounding rocks to create favourable conditions for ruby growth," researchers say.
"Without it, the team’s models showed that it would not have been possible to form rubies in this location."
A paper detailing the findings has been published in the journal Ore Geology Reviews.