[Rockhounds] 2.5 billion-year-old traces of life locked inside primeval ruby

[Kreigh Tomaszewski]

Traces of ancient life were locked inside a 2.5 billion-year-old ruby from
*Greenland* <https://www.livescience.com/61602-greenland-facts.html>,
according to a new study.

The planet's oldest rubies, sparkling red gemstones made up of a
transparent red mineral called corundum, are found in Greenland. 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*
<https://www.livescience.com/28698-facts-about-carbon.html>, that may be
the remains of ancient microbial life.

"The graphite inside this ruby is really unique," Chris Yakymchuk, a
professor of Earth and Environmental Sciences at the University of Waterloo
in Ontario, Canada, *said in a statement*
<https://uwaterloo.ca/news/media/some-worlds-oldest-rubies-linked-early-life>.
"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
analyzed the ratio of different versions, or isotopes, of  carbon in the
graphite, according to the statement. More than 98% of the carbon on the
planet has a mass of 12 atomic mass units, but some carbon *atoms*
<https://www.livescience.com/37206-atom-definition.html> 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 in this graphite, we concluded that the
carbon atoms were once ancient life, most likely dead microorganisms such
as cyanobacteria."

https://www.livescience.com/ancient-life-inside-primeval-ruby