Geologists to Reveal New Formation Mechanism of Diamonds

This week, British Journal Nature-Communications released a piece of geology paper, which illustrates and explains how to form the new mechanism of natural diamonds. According to this new model, in the interaction between water and rock deep in the earth, the decline of acidity (pH) will be able to bring the deposit of diamonds.

In the past, the cause of formation of diamonds has been attributed to redox reaction of magma or liquid deep in the earth. Scientists believe that it begins with carbon dioxide and methane as the chemical reaction, and these organic species provide a series of different initial materials, and ultimately create a diamond. However, people’s understanding for these reactions is very limited, and the influence of pH change has never been studied.

Dmitri WeiErJie team from Johns Hopkins University built a theoretical model in the past-the water model deep inside the earth, and published it in Nature, which reveals the details about the carbon in the depths. The underground carbon may affect the origin and history of life on earth, which contains mantle fluid of organic carbon species that should create diamonds in an unknown way.

This time, WeiErJie team used the theoretical analysis model to simulate the forming conditions of the diamond, and they also use aqueous liquid and elevated temperature and pressure. Through the simulation of flow change of liquid and the interaction with silicate rocks, they eventually found that the interaction between liquid and rock results in the decrease of pH value, resulting in a suitable condition for diamond precipitation.

In the above phenomenon, it does not appear redox reaction that explained diamond formation in the past, but now people still believe that the previous theory may be still valid in some cases.

A new model is useful for the study of different natural conditions of diamond formation, and it can be expanded to include more complex parameters. In the end, such research can help to solve complex history of geological time and the liquid deep inside the earth.