Today, most diamonds are cut as round brilliant cuts. This is a circular, symmetrical cut, where every facet (apart from the top facet or “table”) is either a triangle or kite shape. However, for hundreds of years, the most common shape of diamond was a cushion cut. It can be considered the predecessor of today’s modern round cut.
Cushion cut diamonds are generally square or rectangular in shape. The precise shape depended on the shape of the rough gem, because at the time there was no way to cut across and reshape the round, all polishing was based on grinding down the rough.
Cushion cut diamonds tend to have a higher depth percentage than a round brilliant cut. They will also have a smaller table facet, and steeper angle from the edge of the diamond to the table (crown angle). The net result of these variations is to break light up to a greater degree than a round brilliant cut stone will do. So cushion cut diamonds will have more fire and exhibit more flashes of colour than a modern cut. The price to be paid for this is a loss of about 1% of light through the base of the diamond, generally unnoticeable to the human eye.
A very good example of this is the following photo, of a two carat D colour diamond:
The diamond is a circular cushion cut, from around 1860. You can see that the table is very small, less than 50% of the width of the diamond (Modern diamonds will have a table of about 58-65%) The most striking thing about the photo is the colours coming out of the diamond. There is strong yellow, purple and blue, and an intense contrast pattern. The stone is lively and vibrant in any light source.
The second example is a 1.19 carat cushion cut diamond
Keep an eye on the red flash in the top centre of the diamond; the next image show why cushion cut diamonds are among the most beautiful diamonds in the world. Because of the cut, the colours displayed can be amazing. The colour moves from red to yellow, with only a tiny change in the angle of viewing. This is significant because when the diamond is worn on the finger, tiny movements of the hand will make it dazzle.
One final image sums this up very nicely! It is a two carat F colour stone, circa 1860. At the top right can be see a yellow and red flash, all in one facet. This is an unusual effect, and makes the stone lively and vibrant.
Another interesting old cut, French cut diamonds are among the most beautiful of diamond shapes. They are typically small stones, and are generally used to adorn the sides of a diamond solitaire, or in eternity rings.
They date back to the fifteenth century, when they were very popular with royalty. They are square in outline, with a diamond shaped table (top facet). They have wonderful fire, and are lively, vibrant stones. The origin of the name is unknown, it is not to do with where they were cut, as these stones were cut all over Europe.
Rose cutting in diamonds is a very old and rare way to fashion a stone. They are typically round, with a flat bottom and a domed, faceted top. Sometimes they can be triangular in shape, but this is unusual. Most often, they have 3 or 6 way symmetry on a flat base.
Very early, basic examples can have as few as 6 facets; over time they were cut more and more intricately, to have as many as 24 facets. In early examples, the cutter simply followed the line of the rough diamond. When they have 3 facets, an optical illusion makes it seem as though they have 9 facets. This inspired cutters to try adding more facets, which led to the development of the full rose cut.
Typically they date from the Renaissance period; by the mid-18th century they were almost totally replaced by the brilliant cut.
They are a dazzling type of diamond, with a rich, large, unique type of fire. No other type of cutting is quite the same as a Rose. In ten years we have only had 4 engagement rings with Rose cut diamonds (as far as I remember!!!!). It is slightly oval, with the full 24 facets. It dates from about 1700, and is set in a modern cluster setting. Viewed in daylight, it is captivating and beautiful.