You have probably seen manufacturers of glass frames scoring the surfaces of sheets of glass with a pen-like instrument, then neatly snapping them into two. The cutting edge of this tool is made up of small razor-edged diamonds. Even the huge drills used for boring through hundreds of feet of rock strata in the search for oil are fitted with diamond cutting edges. It is the extreme hardness of the diamond which makes these tools so effective. The diamond is, in fact, the hardest known naturally-occurring substance. It cannot even be scratched. Put it in acid, and there will be no effect.
But there is another aspect to this wonderful stone. If it is heated to a very high temperature it will disappear. It will simply sublimate into carbon dioxide, and if struck a sharp blow at exactly the right point, it will break asunder. You need only look at diamond gemstones to see what exquisite, multi-faceted forms they can be given by jewellers, because by studying the inner structure of the diamond, they know exactly where and how to break them.
“If the upright human soul is to be revealed in all its beauty, it must be given the same delicate handling and treated with the same expertise as the master craftsman lavishes on a superb but fragile piece of jewellery.”