The ancient Chinese were the first to use diamonds as tools thousands of years before than previously believed.
According to researchers, ancient people of the Stone Age in China were the first to use diamonds as a tool, and that two thousand years before someone else came up with the great idea.
Paradoxically, diamonds were used to polish jade with which ceremonial axes were made. Researchers had previously thought that the stone used to burnish the ax was quartz.
However, a team of Chinese and American scientists of the Harvard University argue that such a degree of polish in the ceremonial instruments could not be achieved with the use of quartz, thus, ancient man most likely used diamonds thousands of years ago.
The team, led by physicist Peter Lu, studied four axes, one of those is at least 4,500 years old using X-rays and electron analysis.
According to researchers, the most abundant material in the axes is corundum, which in its red form is known as ruby and sapphire.
Previously, researchers believed that most prehistoric objects were made with the use of rocks which contained minerals not harder than quartz. However, corundum is one of the hardest minerals in nature, only diamond are harder.
It was thought that the first diamond was used as a tool in India around 500 BC.
Peter Lu, a researcher that was part of the scientific team, said that they now have evidence that proves that ancient man used diamonds thousands of years before than previously thought.
The scientists were amazed by how the surfaces of the axes were polished, they took a sample of stone of one of the axes and subjected it to a process of polishing with diamonds, silica and alumina.
Then they observed the surface with an atomic microscope at a nanometric scale and found that the part that resembled the oldest piece was the one that had been polished with diamond tools.
“So far, based on written evidence, it was believed that the first diamond tools were used in India around 500 BC. This, although probably true, is just speculation,” said Peter Lu in an interview with BBC.
“Now we have physical evidence that supports our theory that diamond tools were used 2000 years before we initially thought… No experiment gives 100% certainty, but this is the only possibility that is logical,” he added.
Curiously, even with the best modern polishing techniques, the team failed to replicate smooth and flat surfaces such as those of the ancient ax.
The authors speculate that the use of diamond and corundum may explain the large number of finely polished jade artifacts that occurred during the Chinese Neolithic.