A quarter of all the diamonds on sale around the world are blood diamonds, meaning they were mined in a conflict zone then sold to finance civil war. There’s no way to know which is, or is not, and so a new market has emerged featuring ethically sound lab-made diamonds that are identical to the real thing.
It takes extreme heat and pressure for carbon to crystalize. In nature, this happens hundreds of miles beneath the Earth’s surface. The ones being mined were shot out by a volcano millions of years ago. So how have scientists managed to hack such an intense and time-consuming process? They began by investigating the mechanisms behind diamond formation, zooming in at the atomic level.
It took decades to develop a way to turn accessible materials into synthetic versions of the valuable stone. And ever since they figured it out over 60 years ago, they’ve been doing it. However, the process requires an excessive amount of energy and catalysts (which can diminish the quality of the final product) to trigger the transformation.
A couple of years ago, a team of researchers said they’d created artificial diamonds that don’t have imperfections. They have the same physical structure, and chemical composition as a natural diamond as the catalyst is methane, not metal. But still, it takes ten weeks to produce a marketable diamond, and lots of power is required to keep the oven heated up that long.
This can be used to make gorgeous pieces of jewelry. People like to get a 1 oz silver bar to use as mixing material so they can make rings, pendants, and earrings with the diamonds. But scientists were determined to make it quicker, cheaper, greener, and cleaner. And they have now succeeded.
The thing is, the unique stone is useful for more than just making beautiful jewelry. It’s physical properties (optical transparency, high thermal conductivity, chemical stability, and extreme hardness) make it an essential material for applications in quantum computing technologies, medicine, and biological sensing. This is why a team of researchers at Stanford’s School of Earth, Energy & Environmental Sciences set out to find a simpler, cleaner, and less energy-intensive way of making a synthetic diamond.
Sulgiye Park, the study‘s lead author, said:
“We wanted to see just a clean system, in which a single substance transforms into a pure diamond, without a catalyst.”
The team found a method that does just that! It involves a hydrogen and carbon molecule found in fossil fuels and a blast of a laser in a pressurized chamber. That is all.
Stanford geologist Rodney Ewing, a co-author on the paper, said:
“What’s exciting about this is it shows a way of cheating the thermodynamics of what’s typically required for diamond formation.”
The molecules are in powder form that looks like rock salt. The material was extracted from tanks of petroleum and refined. Under a microscope, the powders consist of atoms organized in the same way as atoms that make up diamond crystals, albeit small fragments of one, two, or three cages. The researchers used a tiny amount so small they used a needle to pick up a sample for observation under the microscope and use it in the experiment.
There was one difference; while diamond is made of pure carbon atoms, the powders (known as diamondoids) also contain hydrogen. The process, however, removes the hydrogen atom altogether, leaving only carbon, and it takes only a fraction of a second.
Stanford mineral physicist Wendy Mao, who leads the lab where Park performed most of the study’s experiments, said:
“Starting with these building blocks, you can make a diamond more quickly and easily.”
Unfortunately, the technique can only produce specks of a diamond, which are not useful for many applications. But now they know more about making pure diamonds with surprisingly little energy and no catalyst, so there is an opportunity to evolve the technique.
