Do you know what a diamond is? Its chemical composition is carbon (C), and natural diamonds can only be called "diamonds" after being polished by diamonds. Natural diamonds are very rare, with only 2 diamonds weighing over 1000 carats (1 gram=5 carats) in the world and only a few diamonds weighing over 400 carats. The largest diamond discovered in China to date weighs 158.786 carats, which is known as the "Changlin Diamond". Rare things are precious, and precisely because natural diamonds that can be used as "diamonds" are rare, people want to replace them with "artificial" diamond, which naturally reminds them of the "twin" brother of diamonds - graphite.

The chemical composition of diamond and graphite is carbon (C), which scientists refer to as "homomorphic variants" or "allotropes". From this term, it can be inferred that they share the same "quality", but their "form" or "nature" are different and vastly different. Diamond is currently the hardest substance, while graphite is one of the softest. Everyone knows that pencil leads are made from a mixture of graphite powder and clay. If there is more graphite powder, it is soft, represented by "B", and if there is more clay, it is hard, represented by "H". Mineralogists use Mohs hardness to represent relative hardness, with diamond having a Mohs hardness of 10, while graphite has a Mohs hardness of only 1. The significant difference in hardness between them lies in the significant differences in their internal structure.

The carbon atoms inside graphite are arranged in a layered manner, with only three carbon atoms connected to each other. Carbon and carbon form a hexagonal ring, and an infinite number of hexagons form a layer. The connection between layers is very weak, while the three carbon atoms within the layer are firmly connected, making it easy for the layers to slide under force. This is why graphite is very soft and able to write.

The carbon atoms inside diamond are arranged in a "skeleton" like three-dimensional space, with four carbon atoms connected around each carbon atom. Therefore, a skeleton shape is formed in the three-dimensional space. This structure has uniform connection force in all directions and strong connection force, making diamond have high hardness characteristics.