As you all know, diamonds are the hardest material on the earth. It is measured with Mohs scale of hardness with 10. However, the scale does not give us solid idea how hard the diamonds are. Therefore, I have done two experiments in the past.
With my first experiment, I tried to break rough diamonds using a vise. The vise was made of iron. After the pressure was applied, the vise did not have any space in between. However, the diamonds did not break. Instead, the vise had small dents.
For next experiment, I overheated the rough diamond when it was polished. In order to polish or cut diamonds, you need to find out right direction. If you try to polish it with wrong direction, the diamond would not be polished even after hours. The diamond glowed with the frictional heat. I closely observed to see when it started to burn. However, it never did. That proved the hardness of the diamond.
On the Mohs scale, topaz is hardness 8 and rubies and sapphires are hardness 9. If the difference between hardness 8 and 9 is multiplied by 100, it equals the hardness of the diamond.
* Mohs hardness: a unit of measurement used to quantify the hardness of a mineral
