While analyzing some of the world's oldest colored gemstones, researchers from the University of Waterloo in Ontario, Canada, found carbon remains preserved in a sapphire over 2.5 billion years old, a period when Earth was It is only inhabited by early life forms such as cyanobacteria, due to the lack of oxygen in the atmosphere, according to researchers.

graphite early life guide

The team of Chris Yakimchuk, Professor of Earth and Environmental Sciences at the University of Waterloo, has begun studying sapphire geology to better understand the environmental conditions needed for sapphire to form.

During their research in Greenland - which contains the oldest known sapphire deposits in the world - the team found a sample of sapphire that contains graphite, a natural mineral of pure carbon, and the results of its analysis showed that it is of organic origin and dates back to the remains of early life on the planet.

The presence of graphite gives us more clues to determine how sapphires are formed at this site (Shutterstock)

Yakimchuk said - in a press release published on the official website of the University of Waterloo on October 21 - that "the graphite found inside the sapphire sample is truly unique, and it is the first time that we see evidence of ancient life in sapphire-bearing rocks."

"The presence of graphite also gives us more clues to determine how sapphires formed at this site, which is impossible to do directly based on the color and chemical composition of the sapphire," he added.

Graphite is a key factor

Sapphire is made of a variety of the mineral aluminum oxide, a crystalline form of aluminum oxide, that forms at the Earth's tectonic boundaries where tectonic subduction and collision provide the intense heat and pressure needed to successfully form sapphire.

The colors of sapphires vary according to the rare element chromium, as the redness increases as the percentage of chromium increases in it.

It is known that sapphire does not form in environments that contain a lot of silica.

Accordingly, the presence of graphite suggests that a liquid must be present that will help rid the rock of silicon dioxide, creating the surrounding environment for sapphire formation in the first place.

Graphite altered the chemistry of the surrounding rock to create the conditions for sapphire to form (Getty Images)

Here, it can be said that the graphite worked to change the chemistry of the surrounding rocks to create favorable conditions for the formation of sapphires in this location.

Thus, researchers have proven - through their study published in the journal "Ore Geology Reviews" in issue 138 of 2021 - that graphite not only links sapphire with ancient life, but is also likely to be an essential element in its formation.

Carbon isotopes and ancient life

The team looked for carbon isotopes in graphite, which are forms of the same element with different numbers of neutrons in the nuclei, with different atomic masses.

When analyzing a property called the isotopic composition of carbon atoms, which measures the relative amounts of different carbon atoms, the researchers found that more than 98% of all carbon atoms were carbon-12, in addition to the presence of some carbon-13 and carbon-14 atoms.

Researchers found an increase in the amount of carbon-12 in graphite (Getty Images)

According to a report published on the Science Alret website on October 22, Yakimchuk explained, "Living matter is mainly composed of lighter carbon atoms because it consumes less energy to be incorporated into cells."

"Given the increased amount of carbon-12 in this graphite, we concluded that the carbon atoms were once an ancient form of life, and we suspect that they belong to dead microorganisms such as cyanobacteria."