Have you ever wondered how it is that jewelers go about cutting the hardest substance on Earth? In case you didn’t know, there is a scientific hardness scale (Mohs Hardness Scale) used to rank the relative hardness of any substance. Diamonds are at the top, beating out even metal alloys. So how do we cut them? There have been a number of techniques utilized throughout history, some of them workable but unbelievably risky. And today, of course, we have new and improved methods that allow more people than ever to enjoy these precious gems in a cut and polished state.
Originally, diamonds were cut with a chisel and mallet, a process known as cleaving. Jewelers took a gamble with every cut. Because they had to look for a weakness in the stone in order to make a cut (and the technique could be considered imprecise at best), there was always the chance that the diamond would be irreparably damaged in the process. The idea was to create smaller stones without (or with less) flaws, but who knows how many truly spectacular gems were ruined through this method?
Ancient jewelers also utilized other diamonds in the cutting process, a method that is still used today (although in a more refined form). But while the original practice involved lubricating one diamond and grinding it against another (positive barbarity!), a more modern iteration of the technique, developed in the 1400s, involved using an instrument called a scaif. This polishing wheel requires a combination of diamond dust and oil to refine a stone that is held in a sort of padded vice called a dop. This allows the jeweler to polish the stone more precisely. So far, it’s a lot better than the chisel method.
However, there was still one innovation to come: the diamond saw. This handy tool came into being in the 20th century as a way to cut hard or brittle materials such as stone, brick, glass, and of course, diamonds. The idea behind it is similar to the scaif, only it is much more efficient. The scaif is a cast-iron wheel which either has diamonds embedded in it or requires that diamond dust and oil be added by hand. The saw, on the other hand, consists of a steel blade with diamond dust bonded to the teeth, which makes for a smaller, more exact tool that cuts better and faster.
While the process for cutting diamonds has improved over the centuries, many techniques that were used in the past are still practiced today. And they will likely continue to be utilized in the creation of beautiful diamond jewelry until the day that a harder substance is found to revolutionize the cutting process. Don’t hold your breath.
