With our current technical level, we can know that the diamond in the Diamond cup grinding wheel are composed of carbon structure, but in ancient times, people's technical level is not high, how to determine its structure? This really took a lot of effort.
In ancient Greece, many philosophers believed that diamonds consisted of four elements: earth, air, water and fire.
In 1704, Newton conducted a systematic study of diamonds and finally confirmed the flammability of diamonds.
In 1772, French chemists discovered by burning diamonds that the gas produced during the combustion process was carbon dioxide.
It was not until 1796 that British chemist Knight concluded that diamonds were pure carbon. Before this, everyone associates diamond with carbon.
But why is there such a big gap between the hardness of diamond and carbon in the same carbon structure?
We still have to start with the source of the diamond.
In 1870, the world's first primary diamond mine was discovered in Cape Town, South Africa. This place is named after Lord Kimberley, then British Colonial Secretary. It was Kimberley City that was discovered. Therefore, the diamond mother rock is called kimberlite.
So far, the Kimberley diamond mine in South Africa has unearthed nearly 2,700 kilograms of diamonds, and the South African government is also trying to apply for the Kimberley mine as a world cultural heritage.
Later, people found the same parent rock all over the world and confirmed that Kimberlite is the only diagenetic diamond parent rock.
Since then, through exploration and experimentation, it is believed that diamonds crystallized from the free carbon contained in the kimberlite itself during the process of violent ascent and explosion, and under high temperature and pressure. People also began to produce artificial diamonds on the assembly line on this basis.
Despite the discovery of so many diamonds, the source of the diamonds is still unclear.