It is common knowledge that diamonds are made from carbon deep into the Earth and with lots of pressure. As far as most people know, diamonds are formed under certain conditions in specific parts of the Earth that scientists cannot directly sample as they do not have a way to drill to the Earth's mantle and travel there.

Now, a new study by Australian scientists claims that the deepest diamonds were most likely formed by nature through recycling wastes, such as former living organisms. They theorized that this process happens 248 miles (400 kilometers) below the surface.

Diamonds are Made From Recycled Former Living Organisms, Study Claims
(Photo: Pixabay)
Diamonds are Made From Recycled Former Living Organisms, Study Claims

Deep Diamonds Originated From Recycled Organic Carbon

Phys.org reported three types of diamonds, including oceanic, super-deep continental, and lithospheric diamonds. Each of them was formed at different locations of the Earth's mantle and had a different mixture of organic and inorganic carbon.

The study, "Oceanic and Super-Deep Continental Diamonds Share a Transition Zone Origin and Mantle Plume Transportation," published in Nature's Scientific Reports, found that oceanic and super-deep continental diamonds shared common origins of organic carbon deep within the mantle.

Researchers said their findings offer a fascinating insight into how the world's most expensive gem was made. This brings new meaning to the old saying, "One man's trash is another man's treasure."

Lead author Dr. Luc Doucet from Curtin University's Earth Dynamics Research Group said that deep diamonds recycled from former living organisms in the ballooning rocks in the mantle, also known as mantle plumes, are brought back to the surface via volcanic eruptions.

Zheng-Xiang Li, a John Curtin Distinguished Professor and co-lead author of the study, said that their research provided a model that explains how all three major types of diamonds were formed and where they were formed.

"This is the first time that all three major types of diamonds have been linked to mantle plumes, ballooning hot rocks driven by plate tectonics, and the supercontinent cycle from deeper Earth," Professor Li said in the university's news release.

He added that their study adds information about the Earth's carbon cycle and gives insight into the possible secrets of Earth's dynamic history by tracking the past locations of mantle plumes. This can be done by creating a map of the distribution of continental and oceanic diamonds.

ALSO READ: Ashes into Diamonds - the Science Behind the Making of Synthetic Diamonds


How Do Deep Diamonds Reach the Earth's Mantle?

ABC News reported that the organic material used to make deep diamonds is pulled into the Earth's mantle when two tectonic plates collided in the subduction zones. The tectonic plate that goes down takes with them the material deep into the Earth, much like recycling.

The study suggests that deep diamonds are formed in an area where organic matter from dead plants and animals was located. Earth's engines then turn this organic carbon into diamonds. Like how typical diamonds are made, deep diamonds are also made deep underground with lots of carbon and immense pressure.

Then they are released back to Earth via volcanic eruptions so humans can marvel at their beauty.

RELATED ARTICLE: 2.7-Billion-Year-Old Diamonds Proves That Life-Giving Elements Appeared Shortly After Earth Was Formed

Check out more news and information on Diamond in Science Times.