Traditionally, diamond cutting is the main visual art involving diamonds. This involves removing material from roughly shaped gemstones.
My birthstone artwork follows in this old craft, and I often draw the facets created by the cutter on a diamond’s surface, as well as the reflections seen within the diamonds themselves.
As such I became fascinated with the art of diamond cutting, and it’s rich tradition.
Diamond cutting has changed very little in the centuries since Indian lapidaries found that grinding one diamond against another both dull surface could me made to glisten. Its the diamond’s hardness that produces its unequaled luster – it can be polished to shine more than any other gemstone.
Diamond cutting aims to refract light through the gem so that it sparkles from any angle. 16 carbon atoms that make up diamonds are constructed of a basic cube shape – so light bends through the diamond in a cube, and it’s this movement of light – together with a fine cut – that can shape a diamond into great brilliance and fire.
A modern cutter may analyze a rough diamond for days or weeks, sometimes making plastic models of it, to find the grain in the crystal and decide how to eliminate or minimize the inclusions that otherwise can reduce the gem’s brilliance. Cutting involves a hand-held steel blade inserted along a diamond’s plane line – or they can be cut with a paper thin disk made of bronze coated with diamond dust. The latter is safer, but much slower.
After sawing, a diamond undergoes a process called bruting, or girdling, which is a mounted on a lathe and ground by a second diamond. The grinding shapes the gem at its widest point, or girdle, i.e the round perimeter of the standard brilliant cut.
To create the tiny flat surfaces called facets, that give diamonds their brilliance, the nearly finished gem is held at a precise angle to a spinning, diamond dusted disk – much as a stylus is applied to a turntable.
After shaping – there are eight cuts – pear, brilliant, emerald, marquise etc) the gem is polished, a process that increases flash by creating minute facets, each at optimum angles to those around it.
In the process of cutting and grinding, a stone may lose more than half its size and weight. But with its luminous beauty, a perfectly fashioned smaller jewel can outshine a larger one.
A birthstone artwork in action – here I draw the detailed frame of the cuts and refractions of an emerald-cut diamond. To be able to see these clearly I photograph diamonds in an extremely low-light environment.