It is not easy to get diamonds on earth. These gemstones are quite rare, which has a direct impact on their value. However, on other planets in the Solar System such as Uranus and Neptune, it’s raining diamonds. Scientists believe that extreme pressure who reigns over these planets will compress elements such as hydrogen and carbon to form solid diamonds. These then fall like rain.
On Earth, scientists have found a way to get diamonds like you can see on Uranus and Neptuneand the raw material they used is plastic. During their research, the researchers used high power lasers on PET samples, the material used to make plastic bottles. This process produces very high temperature and pressure capable of forming small diamondssimilar to what one would find on the two giant planets.
The phenomenon of formation of diamond showers on Uranus and Neptune has not yet been observed directly. However, scientists announced in 2017 that they had succeeded in recreate the process in the lab.
The course of the experiment
In their laboratory, the researchers used the most powerful X-ray laser in the world, the LCLS or Linac Coherent Light Source, on samples of hydrocarbon materials. This caused the temperature of the latter to rise to 6000°C and generated powerful shock waves with a pressure of a few million atmospheres. The result was the formation of “nano-diamonds”.
For best results
The first experiments showed that the formation of diamonds was technically possible. However, the researchers indicated that the original hydrocarbon materialssuch as polystyrene, did not accurately simulate the elements present inside the two icy planets. Oxygen is indeed present in large quantities. The scientists therefore looked for other materials that could include oxygen in the experiment.
the PET material was eventually chosen as the core subject. PET has a good balance of carbon, hydrogen and oxygen. The scientists conducted the experiment using two different imaging techniques to verify the formation of nano-diamonds, but also to know their size and rate of formation. Using this method, they discovered diamond densities of up to 3.87 g per cm3.
According to Dominik Kraus, co-author of the study, the effect of oxygen is to accelerate the separation of carbon and hydrogen, which encourages the formation of nano-diamonds.
For scientists, this study lends weight to the diamond rain hypothesis on giant ice planets. It also demonstrates a potential new technique for making these small diamonds that can be used in industrial abrasives.