Not many people know of the bow tie effect on diamonds, but if you’re buying a fancy cut stone, you’re bound to come across this term. While it might sound like something you’d want your diamond to have, in fact, the bow tie effect can significantly reduce the beauty of your stone.
Here’s why the bow tie effect is significant and why it’s best to avoid it. (Note that we’ve used examples from James Allen in this article as their site provides the clearest images of any retailer at the moment).
What is the Diamond Bow Tie?
Simply put, a diamond bow tie refers to a dark horizontal section on the surface of a diamond that looks similar to a man’s bow tie. There are many degrees of a bow tie, with some being faint and others appearing very intense.
The good news is that bow ties don’t affect the most popular diamond cuts – round and princess. They’re commonly seen on elongated fancy diamond cuts, including marquise, oval, pear and sometimes even on heart shaped diamonds.
The images below feature diamonds with intense levels of bow tie.
What Causes the Bow Tie Effect?
The reason brilliant cuts like round, square or cushion don’t feature bow ties is because these are all perfectly proportioned shapes with light distributed evenly throughout the diamond. The fancy cuts mentioned above that show bow ties do so because the reflection and refraction of light is imperfect. If the shape features misaligned facets and a poor cut, the bow tie effect is intensified.
A well-cut pear-shaped diamond
A poorly cut pear-shaped diamond
Another reason that results in a visible bow tie is the way you view the diamond. This factor has nothing to do with the cut itself, but more with how your head blocks the interaction of light with the stone. After all, a bow tie occurs when light doesn’t reflect properly on the stone and if you’re head is in the way of the light, you’re creating shadows which end up reflecting within the diamond.
Is a Bow Tie Always Bad?
Most of the affected fancy cuts tend to have some level of bow tie, although often the bow tie is so faint you can scarcely see it.
Faint bow ties can actually make a diamond look appealing, adding to its aesthetic. It makes the diamond look brighter as it provides a contrast of shadow and light. Also, if there’s no bow tie at all, it could be a sign that the diamond has been cut too shallowly which results in decreased sparkle.
But if the bow tie is the only thing you notice when you look at the stone and there are large chunks of blacked out sections across the diamond, it’s best to avoid it.
Take a look at the 360-degree video of this pear shape diamond that features a strong bow tie. Regardless of what angle you view it from, you can see the dark shadows in the diamond. Notice how the dark sections are especially intense from the face up view.
The Trouble with Grading Reports and Bow Ties
When most people buy a diamond, especially online, they tend to rely on the grading report to validate that the diamond is beautiful and well worth the money they’re spending.
Unfortunately, the grading report makes zero comments on the diamond’s visual flaws like windowing, extinction, locations of inclusions or the presence of bow ties. You could have two diamonds with identical grading reports, but one could have a severe unsightly bow tie.
The diamonds in the selection before all show some bow tie effect, but some are worse than others. On their grading reports, all these diamonds would be very similar to each other. The only way to cherry pick the best is to carefully view each stone.
Random selection of pear cuts from James Allen featuring varying levels of bow tie.
Because of this it’s extremely important that you view the diamond you’re purchasing before you buy. If you’re buying online, ensure that there are HD images and 360-degree videos of the actual stone, showing you how it looks from all angles.
For this, we recommend searching on James Allen simply because their diamond display technology is undoubtedly the best. The diamonds can be zoomed by up to 20x magnification, making it even better than viewing it in person. Other top retailers like Blue Nile and With Clarity are catching up in terms of technology, but as of now, James Allen still ranks as the best in this department.
To see this up close, click on the image below and check out the Super Zoom and video features.