What’s the difference between an old cut and modern round brilliant cut diamond?
If you have had a look at our collection, you will see that we love old cut diamonds! They appear in original, period pieces but we also love to incorporate them into new items of jewellery. Reusing beautiful old stones is by far the most sustainable way to enjoy jewellery, and this way you don’t have to worry about the delicacy of antique jewellery for everyday wear. Old diamonds have their own unique charm, but they may not be for everyone. If you are unsure about what they are and how they differ from modern diamonds, then this post is for you.
The modern round brilliant cut was developed as recently as 1919 by a gentleman called Marcel Tolkowsky. He was an engineer who calculated the ‘ideal cut’ for diamonds for his PhD research. He identified the ‘ideal’ proportions and angles of the 57 facets of a round diamond to maximise the return of light within the stone, and therefore produce the best visual effects. The detail gets very technical, which we don’t need to go into, but the main concept to grasp is to think of the physics of light travelling through a diamond, within it, and how different surface angles may change its direction. If the light leaves the stone in the wrong place, it creates dark patches and ‘gaps’ in the overall view. For a modern diamond, the light enters through the top of the stone, (the table), and is reflected within the stone and back out through the top and into the viewer’s eye. As the technology of the twentieth century has evolved, so too has the precision capabilities of the machines used to cut diamonds. So, today, a modern round brilliant diamond is cut within strict mathematical parameters to produce optimal sparkle.
Of course, before this, people had been cutting diamonds for centuries and many others had tried to develop new cuts and styles. There are many diamond cut variations dating from the middle ages, to Tolkowsky’s ‘ideal cut’ and beyond. However, we are not going to complicate things. We are going to focus on the most common older cuts: rose, old mine and European.
The rose cut was developed during the 16th century, and it continues to appear throughout the 18th century within examples of Georgian jewellery. It may surprise you to know that a rose cut usually has a flat bottom, or is slightly domed. It is also pretty distinctive as it is made up of solely triangular facets, shaped to a slight point at the top. They have a unique sparkle, but you will notice very little fire and brilliance out of a rose cut diamond as there is no flat table, and the stone does not return the light to the eye of the viewer in the same way as later cuts.
Old Mine Cut
An old mine cut generally refers to an older style of diamond cutting that you may see in Georgian and earlier Victorian jewellery. They were later called ‘old mines’ as a way of differentiating from the style of cutting prevalent after the discovery of South African diamonds in the 1860s and most likely refer to both the Indian mines (originally thought to be the only location for diamonds in the world) and Brazilian, where diamonds were discovered in 1729. Old mine cuts have 58 facets, and are characterised by being much more cushion shaped or having a more irregular outline. Additionally, they typically have high crowns, small tables, and a large culet facet, clearly visible from the table. This is because the cutters had limited technology, and basically had to knock one diamond against another to shape and cut it - so you can imagine that precision was not at all easy!
Old European Cut
You will probably see this as being called an ‘old cut’, which is a more general term, but most commonly applied to this cutting style. Developed in the late 19th century, it is rounder (but sometimes still not quite round!) than an old mine cut thanks to the improvement of cutting technologies. The old European cut also has 58 facets, a high crown, small table and a visible culet facet, yet it’s smaller than those seen on old mine cuts. The facets are chunkier than a modern round brilliant, and produce more of a ‘checkerboard effect’ with light. You sometimes may hear of them being referred to as ‘candlelight diamonds’, which is not a technical term, but describes the flickering nature of the facets with low light levels thanks to this ‘checkerboard effect’.
A key characteristic of these old cuts, is visible evidence of the fact that they were worked by hand. There may be oddly placed extra facets as the craftsman realises his facets don’t quite match up or fit, and he has to stick another one in to fill the void. The facet symmetry may not be great, or the table is not quite in the centre of the stone. All of these aspects add to the character, charm and individuality of old cut diamonds, of which no two are ever quite the same. Of course, change doesn’t happen overnight, and so you may come across a ‘transitional cut’ which displays a mix of different cutting styles such as an old European cut and modern round brilliant - and therefore it doesn’t quite fit into either category. You may also notice that it is much more common for older diamonds to have more of a yellow tint, and possibly be a bit more included than you may expect of a modern diamonds today. You have to remember that these were mostly cut at a time prior to the discovery of African diamond mines, when diamonds were unbelievably scarce - so a greater range was deemed ‘acceptable’ than we may judge by our modern standards.
We have a wide range of old cut diamonds in different shapes, sizes and styles. Browse our collection online or visit us at Burlington Arcade.
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