Guide to Diamond Bow Tie Effect

Elongated diamonds have a way of catching attention. They feel elegant, expressive, and slightly unconventional, which is why they show up so often in the custom engagement rings and wedding rings we design at Alexis Gallery. Along with their appeal comes a recurring point of discussion during diamond selection: the bow tie effect. It is a visual trait that people tend to have strong opinions about, and something we provide education on.

The bow tie effect refers to contrast that appears across the centre of certain elongated diamonds when light does not return evenly to the eye. This can create a darker bow-shaped pattern through the middle of the stone, hence the name. Sometimes this contrast can be influenced by the viewer’s own head and shoulders blocking incoming light.

Let’s walk through what creates the bow tie effect, where it shows up, and how to think about it when choosing a diamond engagement ring.

What is the Bow Tie Effect in Diamonds?

What Causes the Bow Tie Effect

The bow tie effect is not a surface issue and has nothing to do with clarity. It comes from the way light travels through the diamond and where it exits. When facet angles do not redirect light evenly back to the viewer, a slight shadow appears through the centre. In elongated cuts, those areas can form a strong bow tie shaped pattern. All elongated shapes have some shadowing throughout their centre, but a true bow tie is dark and unmistakable.

Diamond Shapes Where Bow Ties Appear

Bow ties are most often seen in oval, pear and marquise diamonds. These shapes extend light across a longer outline than round stones, which increases the challenge of even light returning through the centre. The shadow can vary from a minimal darkening to a very distinct bow tie – higher ratio/more elongated stones can be more prone to bow ties.

Why Bow Tie Strength Differs Between Diamonds

Poor cutting is the main reason bow ties occur. Cutting decisions shape how light enters, moves, and exits the stone. A diamond’s brilliance, facet angles, pavilion depth, and symmetry all influence this behaviour. Selecting a diamond with an Excellent/Very Good cut grade can help ensure strong bow ties won’t be present. A slight shadow that shifts with movement often reflects balanced proportions. A more noticeable bow tie that remains fixed across viewing positions usually points to light escaping through the centre and a poorly cut stone. These differences show up even on flawless clarity diamonds.

How Light and Movement Affect Visibility

Diamonds change character depending on their environment. Bright retail lighting can soften contrast, while neutral daylight often reveals it more clearly. Movement adds another layer. When a diamond is rotated, healthy light return causes contrast to shift and soften, usually creating a sparkle effect. A bow tie shadow that stays dark from most angles tends to interrupt that sparkle.

Can a Diamond With a Bow Tie Still Sparkle?

Yes! Many elongated diamonds show a visible bow tie while still delivering strong brilliance and fire. What matters is how that contrast behaves. If it shifts with movement and does not dominate the centre, the diamond can still feel lively and bright. This is why we always look at diamonds in motion and in real lighting before drawing conclusions.

Does Carat Weight Influence Bow Tie Visibility?

Bow tie visibility is influenced more by a diamond’s face-up shape than its carat weight. Elongated shapes place more visual emphasis on the centre line, which can make contrast easier to notice, especially when the stone has a very high length to width ratio. Highly elongated shapes also force the angles of the facets to become more extreme making exceptional cutting more challenging. Two diamonds can share the same carat weight and show very different bow tie patterns because weight can sit in depth or width. What matters is how the diamond presents from the top and how the cut returns light through the middle.

Do Diamond Reports Address Bow Ties?

Bow ties are not listed or graded on standard diamond certificates. Laboratories focus on measurable attributes such as clarity, colour, carat, and cut. With that in mind, an Excellent to Very Good cut grade does ensure that the ‘mathematics’ of the stone are as close to perfect as possible, removing the risk of a strong bow tie. As part of our curation process, our diamond experts assess and quality check every stone we consider by hand, ensuring any undesirable qualities like bow ties aren’t present. During your diamond viewing, you’ll see your diamond options on hand and in motion, either in person or through detailed HD videos and comparisons.

Can Setting Design Reduce the Effect?

Setting design does not reduce a bow tie effect because it cannot change how the diamond returns light. The bow tie is determined by cut and proportions before the stone is ever set. What a setting can do is influence visual focus. Orientation, prong placement, and metal presence can draw attention toward other areas of the diamond, which may make the contrast less prominent in daily wear, but the underlying light behaviour remains unchanged.

Choosing With Confidence at Alexis Gallery

At Alexis Gallery, diamond selection is never just about numbers or what we have ‘in stock’ (spoiler alert, we don’t have any). We approach curation one by one, with each individual client. Based on your concept, we bring in stones specifically for you, so we’re always fitting stones into your vision, not compromising your dream based on what’s available in a display case (we don’t have those either).

When we’re curating, we’re thinking about how a stone behaves, how it feels once worn, and how it fits into a larger design story. Our experience with custom engagement rings and wedding rings allows us to evaluate diamonds beyond certificates alone. We work with lab-grown and earth-mined diamonds, review stones in varied lighting, and design settings that respect each diamond’s character. If you are exploring a custom piece, contact us! We are always happy to walk through these details with you and help you choose with clarity and confidence.