In 1919 there was a new cut discovered after years of try-and-errors by diamond cutters. They were searching for a way to give a diamond more fire and brilliance, and they found it! The round brilliant cut was introduced and became the most common cut from then till now. It has a lot of resemblance with the old European cut. They still used 58 facets, but made the table bigger and crown lower. We can say they changed the proportions a bit and found a way to make the gemstone perfectly round in contradiction to previous cuts. Because the new shaped crown, light got different ways to fall in the diamond and reflect again in different and more directions.
Because this cut is so pure and stunning, diamond cutters use this type of cut fore all gemstones found in nature. As you can see on these pictures below, a brilliant cut sapphire or ruby can be as wonderful as a brilliant cut diamond.
Furthermore a brilliant cut diamond is not only stunning in any jewel, it’s also a very good investment. As well as gold, diamonds never lost their value during al these centuries. Of course their value fluctuated and will keep on fluctuating during the years. But we can say a diamond has always been expensive/valuable and will always be.