News

Educational Information

The Princess Cut remains one of the most interesting and fascinating of all the Diamond Cuts that I have worked on. What a mysterious shape! It's a practical cut when considering weight retention from the rough stone but totally impractical when considering durability.



The Princess Cut is probably the most misunderstood and least-liked shape by most jewelers that I have spoken to about this subject.
Why it was even invented is an interesting question. In my opinion the Princess Cut scintillates more than most other cuts yet remains the most dangerous and breaks more easily than any of the other diamond cuts. I must receive at least three, four and sometimes more Princess Cuts a week that are damaged and, depending on the degree of the break (chip), need to be repaired or fully recut, sometimes resulting in a large weight loss.

Before I describe how and why the Princess Cut breaks so easily, let us take a look at a brief history of why it was invented.

If I am not mistaken, I believe that the predecessor to the Princess Cut was a Barion Cut that was invented by the highly regarded diamond cutter Basil Watermeyer. Watermeyer, I believe was the first person to take a square Emerald Cut and painstakingly re-fashioned the bottom of the diamond which resulted in a beautiful stone that performed with an enormous amount of scintillation. According to Watermeyer, this took place in 1970.

At this same time, in New York, a diamond cutter by the name of Mr. Henry Grossbard was fashioning a beautiful cut that would become what we now commonly call a Radiant Cut. Both Mr. Watermayer and Mr. Grossbard were way ahead of their time.

It was the diamond manufacturers in Israel who took this one step further. They figured out that more weight could be saved from the rough Octahedron by not cutting the corners, leaving a huge table and leaving the stone without much crown height.

The diamond manufacturers love the Princess Cut because of the economics involved. Why not, wherever possible cut a Princess Cut rather than a Round Brilliant Cut when in most cases a further 25%-30% can be saved from the rough.

Typically the Princess Cut is produced from well-formed Octahedrons which for the most part are sawn and separated down the middle. Prior to the invention of the Princess Cut the same Octahedron was sawn and made into two round stones with the weight retention being between 47% and 53% of the rough diamond. However, cutting the Octahedron into two Princess cuts will yield approximately 75% from the rough which translates into a healthier profit margin for the diamond cutting factory.

In my view, the Princess Cut was invented, or should I say evolved, out of the good intentions of Watermayer whose idea was to give the Emerald Cut more life. So, it could be said that the Princess Cut was created out of a practical need to save more weight from the rough.

Why do they chip and break?

The easy answer is, because of the cleavage plane which runs parallel to the octahedral face. A diamond is the hardest substance that we know of but it is also very weak and brittle particularly along the cleavage plane. The Princess Cut is particularly susceptible because of the way most of them are made.

Let us examine a typical Princess Cut. The bulk of this cut is on bottom, the corners of this stone come to a 90 degree angle, the crown height is very limited with a very low crown angle; add to this a very large and spread table and generally a very thin girdle.

When you add all of these things together what you have is a recipe for a potential disaster. The risk arises, particularly when the stone is being mounted or even when it is being worn. An example would be if the ring were to come into contact with a faucet or a car door at just the right angle, this could definitely lead to the stone being damaged. As a matter of fact this applies to all diamond cuts but, more often than not, Princess, Pear, Marquise and similar cuts that have sharp corners and points.

How to reduce the risk

Obviously if we were to fashion and make a beautiful Princess Cut it would have a small table, a 34 degree crown angle and a crown height equal to that of an "Ideal Cut" Round Brilliant. Add to this, a medium- to slightly-thick girdle which provides the stone with a stable foundation. Perfect, except for the fact that if cut correctly, the weight advantage wouldn't be that much more than a Round Brilliant Cut. That is the reason most Princess Cuts are badly made, to save the weight.

The next time that you pick up a Princess Cut, take a look at the corners -- guaranteed at least to have one or more have small chips. Now this is generally accepted in the trade and is not a big problem except if the chip is very obvious or if the Gem Trade Laboratory has made a determination that the stone in question would be Internally Flawless if the small chips were to be removed.

I am a big advocate of cutting small corners on the Princess Cut. Talk about reducing the risk of damage to the diamond. This simple procedure of cutting corners and creating a 45 degree angle instead of the usual 90 degree angle reduces the risk enormously and can be the difference between a Princess Cut that remains intact and one that gets damaged, sometimes resulting in a large weight loss due to re-cutting.

A friend of mine, a wholesaler who deals in a large volume of Princess Cuts, sends the stones to me to have, as he says, "blunt the corners" (about the size of a small to medium culet) before sending them to the GIA for certification. This process, which takes less than 0.01ct to do, stabilizes the corner and prevents the small chips from occurring. Much like the importance of culet on a Round Brilliant Cut helps prevent the culet from chipping.

As a precautionary measure prior to mounting the Princess Cut, a large number of my Jewelry store customers will send the stone to me so I can cut the corners. The corners that I cut are about the size of a large culet and are not too big and over-bearing. Depending on the size of the stone, the weight loss is 0.01ct - 0.04ct. A really insignificant weight loss when considering the large amount of weight that could be lost if severe damage occurred.

This is hard for me to say, but if the Princess Cut does chip or break, it's better that the damage occur right on the corner because this can be repaired quite easily and without not too much weight loss by cutting corners. The size of the corners would be dictated by the size of the chip. Most Princess cuts are damaged in this manner and the best way out of the mess, is to cut corners on the stone.

However, and this is the worst situation, when one or more sides - from end to end - of the Princess Cut have been literally sheared off. I have seen some really badly damaged Princess Cuts where the side of the diamond has broken off leaving nothing but the table. The whole of the crown has disappeared with the break extending into and up the bottom of the diamond right along the cleavage plain.

In this case the weight loss is enormous; 25% - 45% is not that uncommon. Part of the reason lies in the fact that in order to repair a Princess Cut that has been damaged in this manner, the side or sides have to be brought in so as to create enough girdle to remove the break (chip).

Why, you may ask, does the stone with this type of damage, loose so much weight? Well stay with me on this and I will attempt to explain. When bringing the side or sides, the diameter of the stone is automatically being reduced and, in turn, a large table becomes larger and a deep stone becomes deeper. Therein lays the rub. A no-win situation, because not only do we have repair the break (chip) but now we also have to close the table and reduce the depth to acceptable standards.LAJewelry.com Listing

By Barry I. Rogoff, Master Diamond Cutter