Double-cut brilliant and triple-cut brilliant diamonds from the 1700s were Cushion cut stones instead of a round or circular cut. Cushion cut brilliant stones from that period are today known as old mine cut diamonds.
In the 1800s large diamonds, like the Koh-i-Noor, changed ownership several times. This stone was eventually re-cut to 105 carats for Queen Victoria in 1851 by a stone cutter in Amsterdam. The stone is currently in the Tower of London and is set in Queen Elizabeths crown.
In the 1900s, diamond saws and jewellery lathes made it possible for some of the more modern cuts of diamonds to be created. The round brilliant and modern round brilliant are cuts that consist of 58 facets. The facets are set up to have 33 on the diamonds crown and 24 on the pavilion.
On June 25, 1905, one of the largest rough gem-quality diamonds was found by Frederick Wells in Cullinan, Gauteng Province, South Africa. This diamond is called the Cullinan Diamond and it weighed 3,106.75 carats. The largest stone cut from this massive diamond was called the Great Star of Africa, and it weighs 530.2 carats.
Even with our more modern methods of cutting diamonds, the result of cutting a diamond can still have as much as a 50% loss of the stones total weight. If the diamond is shaped like an octahedron, the round brilliant cut is preferred. This is because two stones can be cut from one diamond. Asymmetrical stones are usually cut in the Fancy style.
A more recent improvement in diamond cutting innovation came in 1919 when a mathematician named Marcel Tolkowsky came up with the ideal proportions of a cut diamond. His formula gave diamond cutters the perfect ratio between the angles of the facets opposite one another in a diamond. In the past, master cutters went through a trial and error process of cutting diamonds, so Tolkowskys formula allowed a cutter to get the maximum inner light of a diamond without having to sacrifice outer light.
With diamond cutting being more precise, it became possible to create machines to polish diamonds. In the early 1960s, a company introduced the Pieromatic diamond-cutting machines. These machines didnt completely automate the process of creating stunning diamonds, but they made the process much easier. They still required trained workers to guide diamonds through polishing operations but long apprenticeships became a thing of the past. Today there is such a wide variety of diamond cuts available that anyone looking to purchase one can find a cut that they fancy.