A team of scientists from the University of Waterloo, Canada, have discovered remnants of graphite in a ruby 2.5 billion years old. A gemstone specimen containing this remnant was found in the city of Maniitsok in Greenland.
O study, now published in the scientific journal Ore Geology Reviews, confirms that there was life there, or rather organisms such as cyanobacteria. To reach this conclusion, the group analyzed the isotopic composition of carbon atoms, 98% of which usually have an atomic mass of 12 (carbon-12). In accordance with Chris Yakimchuk, one of the authors, “living matter preferably consists of lighter carbon atoms, because they consume less energy to be incorporated into cells.”
According to the authors, graphite is found only in rocks with the same or older age, which means a period when there was little oxygen on the planet and only microorganisms were present. In this case, rubies exist only in this rock due to graphite, which has changed the chemical composition of the rocks in this place, creating favorable conditions for the appearance of the precious stone.
“The graphite inside this ruby is truly unique. This is the first time we see evidence of ancient life in rocks with rubies, ”says the expert author. “The presence of graphite also gives us more clues to determine how the rubies formed in this place, which cannot be done directly from the color and chemical composition of the ruby.”
Chris Yakimchuk, Vincent van Hinsberg, Christopher L. Kirkland, Christoffer Silas, Carson Kinney, Jillian Kendrick, Julie A. Hollis, Corundum (Ruby) Growth During Final Assembly of the Archean North Atlantic Craton, Southern West Greenland, Ore Geology Reviews. DOI: https: //doi.org/10.1016/j.oregeorev.2021.104417.
