Monthly Archives: August 2015

Small, ancient diamonds reveal seawater key for precious gems formation

small-ancient-diamonds-reveal-seawater-key-for-precious-gems-formation image www.worldwidediamonds.info

An international team of researchers has revealed that seawater may have played an important role in formation of diamonds hundreds of kilometres underground.

In a paper published Thursday in the journal Nature, scientists from Canada, the U.S. and the U.K suggest diamonds form as a result of plate tectonics carrying seawater into deep parts of the earth.

The team came to such conclusion after they found microscopic, dirty diamonds from the Ekati mine in Canada’s Northwest Territories, home to rich deposits of high and low quality gems.

“Ugly little things”

The diamonds provided to the researchers by Dominion Diamonds aren’t fit for a ring by any stretch of the imagination — they’re far less than a millimetre wide and “fibrous” or cloudy.  Scattered throughout the crystal are droplets of fluid — millions of them, in some cases.

However, the tiny rocks were key to the study. “With the ringwoodite discovery, we showed there is a lot of water trapped in really deep parts of the Earth, which probably all came from recycling ocean water,” Graham Pearson, professor in the University of Alberta’s Department of Earth and Atmospheric Sciences and Canada Excellence Research Chair in Arctic Resources, said in a statement.

“This new study really highlights that process—it clearly demonstrates that ocean water in this case has been subducted via an old oceanic slab into a slightly shallower but still very deep part of the Earth. From there it has pumped that brine into the bottom of the root beneath the Northwest Territories, and it’s made the diamonds,” Pearson added.

small-ancient-diamonds image www.worldwidediamonds.info

Although high-quality gem diamonds are normally estimated to have been formed three billion to 3.5 billion years ago, these poor-quality, fluid-rich diamonds appear to be just a few hundred million years old—significantly younger in the Earth’s geological timeline.

One theory to explain this age difference is that the two types of diamonds are actually formed by similar processes, and then over time the fluid-rich stones transform into the gem diamonds. Pearson and his team plan to do further studies on the fluids found in these diamonds to test this model.

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Henry Sapiecha

Ancient Diamonds Came From Seawater and Future Diamonds Might Come From The Air

Cloudy diamonds give some scientists new clues to how they formed underground, others find ways to make them out of thin air.clear cluster of diamonds with white bg image www.worldwidediamonds.info

They may not be fit for a ring, but microscopic diamonds found in a mine in Canada’s Northwest Territories could be the key to uncovering how the stones form.

It’s pretty well-known that diamonds are formed when carbon is compressed at extremely high pressure inside the earth’s crust. But while time and pressure are important, the gems still form like other crystals, which need a reactive fluid for grow in. Now, a group of researchers say they have uncovered evidence that points to some kinds of diamonds crystallizing in pockets of seawater trapped about 124 miles below the earth’s surface.

“I think it really helped to get the diamond forming reaction going,” Graham Pearson, a geochemist at the University of Alberta who co-authored the study, tells Emily Chung for CBC News. “We would argue having some seawater and brine helps formation because it’s a very reactive fluid.”

The bold conclusion comes from data taken from 11 microscopic diamonds with millions of droplets of fluid suspended within them. When crystals form rapidly, they can sometimes trap pockets of liquid inside themselves. The liquid is often the same reactive fluid that the crystal grew in, leaving clues as to how the gem was formed. Using an analysis technique called spectroscopy, the scientists scanned the tiny, cloudy diamonds for clues of what chemicals the droplets were made of, Chung writes. What they found was water.

“It’s really diamond formation caught in the act,” Pearson tells Chung.

To get a more detailed chemical analysis, the researchers used lasers to vaporize the diamonds. They discovered that the trapped bubbles of water contained high levels sodium and chlorine – the building blocks of salt – as well as strontium, which is strikingly similar to what would have been found in seawater hundreds of millions of years ago, Chung writes.

Pearson believes that the diamonds may have formed when seawater was pushed under the earth by the movement of tectonic plates, where carbon-rich rocks and high pressure would have made the perfect conditions to grow diamonds. While it’s still unclear how these microscopic, cloudy diamonds are related to the one on your co-worker’s flashy engagement ring, it does give scientists new hints to how water and carbon cycle through the earth.

While some scientists are figuring out how diamonds are made beneath the earth over millions of years, others believe they’ve found a new way to make artificial diamonds out of air pollution. A group of researchers from George Washington University announced at a recent meeting of the American Chemical Society that they have devised a method for extracting raw carbon from the atmosphere, Daniel Cooper writes for Engadget.

In a new study published in the journal Nano Letters, the researchers say they have extracted carbon nanofibers from carbon dioxide through an electrochemical process. Carbon nanofibers are strong and lightweight materials typically used in machinery like cars and airplanes, and could also be refined into artificial diamonds for jewelry and electronics. However, while the nanofibers are versatile, they are extremely expensive to make. By sticking a pair of electrodes in a bath of lithium carbonate and lithium oxide, the researchers say they were able to extract carbon straight out of the atmosphere, which could provide manufacturers with a reservoir of cheap nanofibers.

If this system could be made to work on a large scale, it might not just make carbon nanofibers easier to get, but could help to actively reduce the carbon in the atmosphere and global warming, Mike Orcutt writes for the MIT Technology Review. However, it has a ways to go: not only is the technology still in its infancy, but the current demand for carbon nanofibers is nowhere near what would be necessary to put a dent in carbon dioxide levels.

While diamonds made from the sky might help the environment in the future, jewelers will still have to rely on old-fashioned ground diamonds for now.

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Henry Sapiecha