Bow Tie Effect in Diamonds Explained

21 July 2026

The Bow Tie Effect Explained: What Every Diamond Buyer Should Know

The bow tie effect is one of the most discussed features in elongated diamond shapes, yet it is often misunderstood. Some buyers assume that any visible bow tie is a flaw. Others are told to ignore it completely. In reality, the bow tie effect is best understood as a pattern of contrast that can appear across the centre of certain diamonds, particularly oval, pear, marquise and elongated cushion cuts.

At Kinzy London, we assess diamonds beyond the grading report alone. Two stones with the same carat weight, colour and clarity can look entirely different because of their proportions, facet arrangement and light performance. Understanding the bow tie effect allows you to judge a diamond more confidently and choose a stone that feels balanced, bright and refined in person.

What Is the Bow Tie Effect in a Diamond?

The bow tie effect is a dark or shadowed area that appears across the centre of some elongated brilliant-cut diamonds. It is named after its resemblance to a bow tie, with two darker triangular areas meeting around the middle of the stone.

This effect is caused by the way light enters, reflects within and exits the diamond. When certain facets do not return light evenly to the viewer, contrast appears. That contrast can shift as the diamond moves, which is why a stone may look different from one angle to another.

The bow tie effect is most commonly associated with oval diamonds, but it can also appear in pear-shaped diamonds, marquise diamonds and some elongated cushion diamonds.

Why Does the Bow Tie Effect Happen?

The bow tie effect happens because elongated brilliant cuts use complex facet patterns to create brilliance across a stretched outline. Unlike a round brilliant diamond, which benefits from a more standardised facet structure and cut grading system, elongated shapes can vary considerably from one stone to another.

As light moves through the diamond, the centre may reflect the viewer, the surroundings or less light than the ends of the stone. This creates darker contrast through the middle. The depth, table size, pavilion angles, facet alignment and overall proportions all influence how pronounced the bow tie appears.

This is why selecting a diamond by certificate alone is not enough. A grading report can confirm carat weight, colour, clarity and measurements, but it will not tell you whether the bow tie is subtle, distracting or beautifully balanced. Our GIA vs IGI diamond certification guide explains what a report can confirm and where visual assessment remains essential.

Is the Bow Tie Effect Always Bad?

No. A bow tie is not automatically a defect, and a completely bow-tie-free elongated diamond is not necessarily superior. Some degree of contrast can give a diamond definition, depth and visual character.

The issue is not simply whether a bow tie exists, but how dominant it is. A subtle bow tie may only appear at certain angles and can blend naturally into the diamond’s overall brilliance. A strong bow tie may remain dark in most lighting conditions and divide the stone visually across the centre.

The best elongated diamonds usually show an even balance of brightness, contrast and scintillation. They should not appear lifeless through the middle, nor should the ends look disconnected from the centre.

How to Judge the Bow Tie Effect Properly

A diamond should be viewed in motion and under more than one lighting condition. Jewellery-store spotlights can make almost any diamond look bright, so it is important to inspect the stone in softer, more natural lighting as well.

When comparing diamonds, look at the centre of the stone from directly above and then tilt it gently from side to side. Ask yourself whether the central contrast moves and breaks up naturally, or whether it remains fixed and heavy.

You should also compare the bow tie with the overall brilliance of the stone. A diamond with a visible bow tie may still be more attractive than another stone with weaker light return across the entire surface. This is why our bespoke engagement ring consultations include side-by-side diamond comparisons rather than relying on certificates alone.

The Bow Tie Effect in Oval Diamonds

Oval diamonds are among the most popular elongated shapes, and they are particularly well known for bow ties. Their curved outline and brilliant-style faceting can produce excellent sparkle, but the centre must be assessed carefully.

A well-chosen oval should feel bright across the majority of the stone, with the bow tie appearing as a soft area of contrast rather than a deep black band. The outline should also be balanced, without overly narrow ends or an excessively rounded profile.

Length-to-width ratio also matters. A very elongated oval may show more pronounced contrast through the centre, although this is not a fixed rule. Our guide to diamond ratios explains how proportion influences the appearance of elongated stones.

The Bow Tie Effect in Pear and Marquise Diamonds

Pear and marquise diamonds can show a similar central shadow because they also combine an elongated outline with brilliant-style facets.

In a pear-shaped diamond, the bow tie should not overpower the transition between the rounded end and the point. The stone should appear bright and balanced, with no large dead areas near the centre.

In a marquise diamond, the bow tie can be more noticeable because of the shape’s long, narrow silhouette. A well-proportioned marquise should still show lively brilliance across the centre and towards both pointed ends.

Because these shapes are less standardised, in-person selection is especially valuable. The Kinzy bespoke design process allows the setting to be built around the exact stone once its proportions and light performance have been approved.

Can the Bow Tie Effect Be Seen on a Certificate?

No grading report will directly state whether a diamond has a strong or weak bow tie. The report provides measurements, proportions, colour, clarity and other technical information, but the bow tie effect is a visual characteristic.

The Gemological Institute of America explains that cut quality relates to how a diamond’s proportions, symmetry and polish influence its interaction with light. However, fancy-shaped diamonds are not all given the same overall cut grade used for round brilliants.

For this reason, videos, photographs and certificates should be treated as screening tools rather than final proof. The most reliable assessment comes from viewing the diamond directly and comparing it with alternatives.

How Shape, Ratio and Faceting Work Together

The bow tie effect cannot be judged separately from the rest of the diamond. The stone’s outline, ratio and facet pattern all influence the final appearance.

A wider oval may look softer and fuller, while a more elongated oval can appear larger across the finger. A pear diamond with broad shoulders may feel more traditional, while a slimmer pear can look more contemporary. Marquise diamonds can vary from softly curved to sharply elongated.

Facet style also matters. Some elongated cushions show broad, chunky flashes, while others display a more crushed-ice appearance. Neither is automatically better; the correct choice depends on the visual result you prefer.

Our diamond shapes guide provides a wider comparison of the most popular outlines and their individual characteristics.

Why Personal Diamond Selection Matters

Online listings often reduce diamonds to a set of grades and measurements. While these details are useful, they cannot fully capture how a diamond performs in person.

At Kinzy London, clients can personally compare diamonds before approving the centre stone for their ring. We consider the 4Cs, but we also assess spread, ratio, symmetry, facet character and the bow tie effect.

Once the diamond is selected, the ring is developed through CAD design and a wax model so the proportions can be reviewed before manufacture. Each piece is then made through our in-house London workshop.

Frequently Asked Questions

Do all oval diamonds have a bow tie?

Most oval diamonds show some degree of central contrast, but the strength varies significantly. A subtle bow tie can be completely acceptable and may only appear at certain angles.

Can a bow tie disappear in different lighting?

Yes. A mild bow tie may shift or soften as the diamond moves. A strong bow tie tends to remain dark across a wider range of lighting conditions.

Is a diamond without a bow tie always better?

No. Overall brilliance, proportions and visual balance matter more than the complete absence of contrast. Some contrast can give the stone definition.

Which diamond shapes are most affected?

Oval, pear, marquise and some elongated cushion diamonds are most commonly associated with the bow tie effect.

Can I judge a bow tie from a video?

A video can help identify obvious darkness, but it may not show the diamond accurately under every lighting condition. In-person comparison remains the strongest method.

Final Thoughts on the Bow Tie Effect

The bow tie effect is not something to fear, but it should never be ignored. In elongated diamonds, a small amount of contrast can create depth and character. The concern is a bow tie that remains heavy, dark and visually dominant.

The most important question is not whether a bow tie exists, but whether the diamond still looks bright, balanced and beautiful as it moves.

To compare carefully selected diamonds in person, book a private appointment with Kinzy London. Our Hatton Garden team will guide you through shape, ratio, certification, light performance and bespoke design before your ring is made.