2.5 billion-year-old traces of life locked inside primeval ruby - Livescience.com

Traces of ancient life were locked inside a 2.5 billion-year-old ruby from Greenland, according to a new study.

While searching for rubies in the North Atlantic Craton of southern Greenland, a group of researchers discovered a hidden surprise in one of them: graphite, a pure form of carbon, that may be the remains of ancient microbial life.

"It's the first time we've seen evidence of ancient life in ruby-bearing rocks.".

"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 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, 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.

Though ancient, this graphite-containing ruby is hardly the oldest evidence of life found so far.

In fact, there are many studies, a lot of them hotly debated, that claim to have found the oldest evidence of life dating back to over 3 billion years, Live Science previously reported.