Everyone knows that diamond is the hardest natural substance known to man, but we just didn’t know why. Now, several researchers think they may have the answer. In the Journal of Physical Chemistry, a team composed of chemists and mechanical engineers put forth an intriguing new hypothesis on why the diamond is as hard as it is. They suggest that it is not the actual element of carbon that makes it hard, but the way it is specially arranged within the diamond. They have noted that each carbon atom in diamond is surrounding by four neighbors, which directly bond to the central atom. These other four surrounding diamonds, in turn, also bonded with their neighbors providing a very unique structure. This type of bonding hybridization might be responsible for the hardness of diamonds.
The new hypothesis may lead to ways of making new materials that mimic the hardness of diamonds. Of particular attention will be the bonding interaction between neighboring atoms in a material. It was also suggested that repulsive tendencies of non-bonded atoms might also contribute to the hardness of the diamond in different ways, by increasing the corresponding energy. If this theory proves to be accurate, there are many applications that could be discovered, including super-hard materials that not only mimic, but exceed the hardness of diamonds. These could be put into place in industries where diamonds are now used like cutting tools and electronics. That might help to reduce the need to mine diamonds out of the ground for industrial purposes, although gemstone quality diamonds are always preferred to be natural gemstones.
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