DIAMOND SHAPES
If we start with diamonds, the most popular shape is obviously the round brilliant cut. There are also ‘modified brilliant cuts’ where brilliant cut faceting is applied to different shapes of stone. This group includes oval, marquise, heart, pear-shape, radiant cut (relatively new), trillion (triangle), and antique cushion cut (rectangular or square with rounded corners).
Other shapes include the emerald cut, a simpler cut originally devised for softer, more brittle emeralds, and the baguette cut, including the tapered trapezoid baguette. This latter is another very simple cut with few facets which is generally used for side stones. Both emerald and baguette cuts require higher quality diamonds; because they have fewer facets and are less ‘brilliant’ in appearance, any inclusions are much easier to see, so stones with few obvious facets tend to be selected for these cuts. This can make them more expensive per carat on average than other options.
The Asscher cut is another traditional cut for diamonds. Sophisticated and less common than many of the other rectangular shapes, it has a few more facets than the emerald cut, and is usually used for a more ‘square’ shape.
Finally, the princess cut is the square stone with pointy corners which has a lot of facets and high brilliance. It is a popular shape, but it is worth bearing in mind that, although diamond is the hardest mineral known to man, it can be brittle and is not indestructible.
I have seen princess cut diamonds which have been damaged in the corners when being claw-set. This damage is not immediately apparent until the time comes to reset the stones, or even just to repair the inevitable wear on a ring which is worn daily. Dismounting the stones to perform this work reveals the cracks or chips in the diamond corners, so you cannot always know whether any stone is in good enough condition to remount until it is removed from its setting.
Old fashioned diamond cuts. There are older diamond cuts including the ‘rose’ cut, Mazarin and ‘old European’. These have been superseded and are rarely produced now because they have a much lower level of brilliance than modern cuts.
They have their own charm and attractions, but are very difficult to match if you are trying to remount inherited jewellery. Older stones were almost always hand cut, and this inevitably limited what could be done with the stone.