Evidence of ancient life discovered in some of the world's oldest rubies: study

A 2.5 billion-year-old ruby was discovered to have carbon residue, which researchers say was once ancient life.

Their clue was the carbon residue, or graphite, recently found encased inside of some of the oldest gemstones in the world.

“The graphite inside this ruby is really unique. It’s the first time we’ve seen evidence of ancient life in ruby-bearing rocks,” Chris Yakymchuk, lead researcher and University of Waterloo professor, said in a press release.

Some of the oldest ruby deposits in the world are in Greenland. This is where the team discovered a ruby sample which contained graphite -- a mineral made of pure carbon.

Analysis of the material found the graphite in the ruby showed remnants of early life, potentially long-dead cyanobacteria.