WASHINGTON: Diamonds may not be as rare as once believed, but this finding in a new Johns Hopkins University research report won’t mean deep discounts at local jewellery stores.
“Diamond formation in the deep Earth, the very deep Earth, may be a more common process than we thought,” said Johns Hopkins geochemist Dimitri A. Sverjensky, whose article co-written with doctoral student Fang Huang appears today in the online journal Nature Communications. The report says the results ‘constitute a new quantitative theory of diamond formation,’ but that does not mean it will be easier to find gem-quality diamonds and bring them to market.
For one thing, the prevalence of diamonds near the Earth’s surface — where they can be mined — still depends on relatively rare volcanic magma eruptions that raise them from the depths where they form. For another, the diamonds being considered in these studies are not necessarily the stuff of engagement rings, unless the recipient is equipped with a microscope. Most are only a few microns across and are not visible to the unaided eye.
Using a chemical model, Sverjensky and Huang found that these precious stones could be born in a natural chemical reaction that is simpler than the two main processes that up to now have been understood to produce diamonds. Specifically, their model — yet to be tested with actual materials — shows that diamonds can form with an increase in acidity during interaction between water and rock.
“The more people look, the more they’re finding diamonds in different rock types now,” Sverjensky said. “I think everybody would agree there’s more and more environments of diamond formation being discovered.”
Nobody has yet put a number on the greater abundance of diamonds, but Sverjensky said scientists are working on that with chemical models.
If the study doesn’t shake the diamond markets, it promises to help shed light on fluid movement in the deep Earth, which helps account for the carbon cycle on which all life on the planet depends.
