Hello!
I have been reading about "shallow" cuts on the internet. It seems as though some people opt for this so that the diamond width is increased for the same carat weight. However, I understand this makes the diamond less brilliant. All the examples and diagrams I have seen have related to brilliant cut diamonds. My question is, do people ever get other diamond shapes (e.g. princess, oval, etc..) cut in an extra shallow form?
Thanks very much for any help! :-)

Great question Docdiamond!
A pet peeve of mine is the plethora of information you can find online.
The problem is that information that, taken in context, might be useful, is extremely misleading when taken out of context.

The depth of a diamond is a good example.
If we're talking about a modern round brilliant, the range of acceptable depths is rather narrow.
Say, 58%-63%. If we stray too far from these depths, it will be painfully obvious, as the diamond won't look like a pretty diamond.
To speak in rough terms, if it's too deep, the center of the stone is noticeably dark. Too shallow and you get a ring inside the diamond that looks like a "Fish Eye"
If we're talking about round diamonds specifically, the pundits have found ways to argue about the subtle differences within the acceptable ranges.

Once we broaden the conversation to include Fancy shaped Diamonds, the range of acceptable depths becomes vastly more inclusive.
A cushion might look amazing with a depth of 50%, or a depth of 75%.
Again, speaking in rough terms, if we are comparing two 5.00carat diamonds- one 50% depth, the other 75%, the more shallow stone should have a larger spread- meaning it will look like a larger diamond.
Without question, a diamond can be too shallow- but there's really no hard fast rules on this.
If there's a problem with the cut, it will be easily visible to an observer.

Now, if we take the other side of this coin, and consider it from a shopper's perspective, it gets even more convoluted.
Your question was the following:

I can see you've been reading up on this- and your question is natural based on a lot of what's written.
The reason it's not really accurate is that it would seem to suggest that the cutter is choosing to cut a particular diamond shallow, or deep.
But the fact is that the rough diamond is what will determine the cutter's actions.
If we compare to real estate, I can use an analogy.
Say there's a piece of land. Let's say the land has a hill on it.
The smartest architects will build a house using the "lay of the land"
When the cutter is deciding how to cut the rough diamond he must also consider what God has created- and using it to it's best advantage.
Remember that a 10carat rough diamond may polish out to a 6carat polished diamond- the rest is gone forever. That means a cutter needs to consider how to balance wasting as little as possible, while creating a beautiful well cut diamond people will want to buy.

My mom has a 3.5 ct light orangey yellow marquise (graded by GIA) with a 49% depth.  I think it is awesome!!!  It sparkles like crazy and appears to be well over 4 cts.

Thank you so much for all your detailed interesting answers, and the beautiful illustrative photos! This greatly appreciated. I am trying to understand the field properly! :-)

What about older cuts, like the OMC, which I find are generally deeper?  Are they darker in the center?

Mikla

Good question Mikla!
One of the aspects of Fancy Shapes that makes them so interesting, also make them better for cutting, in some ways.
For example, the cutter is handcuffed with a round- it has to look a certain way.
Fancy Shapes can have large facets in places you can't put them on a round. This allows the cutter a lot more freedom to cut a stone with great life- regardless of the depth.

I'm finding it interesting reading all your replies :-) Thank you!
It's a nice group here! Are you all jewellers?
I am trying to write some articles on diamonds as precious gems for my partner's website. He knows quite a bit about the "physics" of diamonds and wants me to research the gem side of things for the website. I think I will be able to learn a lot from this forum :-)

Most of us are just, let's say, obsessive-compulsive magpies.   

We love diamonds, and like learning about them.

Thanks DiamondHunter!
I'm afraid his knowledge is more about the crystal structure of diamond and what makes it a good semiconductor. Maybe he knows about how the structure affects how light interacts with diamonds of various cuts, I'm not sure. I will ask! :-)

David, that made me smile - there are probably people out there who would not only count the brush strokes but would tell you why you ought to do that as a matter of course when you buy art. Heck, they'll probably invent a machine that will scan artwork and tell you how many brush stokes there are and at what angle...


Jen

Perhaps there are just too many diamonds. Pages of websites giving you statistics on stones that no one has seen with advice on how to judge. If there were fewer stones we would be more accepting of differences and aware of personality. Try finding a perfect 2 carat round cut alexandrite,  I would gladly have a shallow cushion windowed one instead as I'm sure it exists. Own what you fall in love with, or get a perfect mail order bride.

I don't believe there are too many diamonds...but maybe too many opinions.
Preferences spoken as they are written in stone physics.

I can see your point about Alexandrites- since they are so very rare, people might be more open minded about their beauty.

Don't dismay though- over the years we've found that many people love to look at a diamond based on artistic, rather than pseudo scientific parameters.