---
title: "The bow-tie effect"
description: "The bow-tie effect in oval, pear and marquise diamonds: what it is, what causes it, what reports miss, and how to check for one and fix it."
url: https://digitalgemology.com/learn/bow-tie
image: https://digitalgemology.com/img/learn/EZGJVq14WXA.jpg?v=edad84fa
---

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[Learn](https://digitalgemology.com/learn)

# The bow-tie effect

Nine lessons · three videos · read them in any order

A bow-tie is a dark band across the belly of an oval, pear or marquise. These pages test it on two marquises with the same outline and facets: DG-Bowtie, which has a band, and our Marquise, which doesn't. We use the light map of our 3D Gemstone Simulator, Brightness & Tilt Analysis and the Cut Performance Wheel to test four published explanations, then fix one stone and give you a routine to check any other.

New here? Start with [Fixing a bow-tie: the steep belly of DG-Bowtie](https://digitalgemology.com/learn/bow-tie/how-to-fix-a-bow-tie).

1. 1 · Video
  ## [The bow-tie effect in diamonds: what it is](https://digitalgemology.com/learn/bow-tie/bow-tie-effect-in-diamonds)
  What a bow-tie is, the parts of an elongated stone, and how to read the four colors of our light map.
2. 2 · Article
  ## [Which diamond shapes get a bow-tie: oval, pear, marquise and more](https://digitalgemology.com/learn/bow-tie/which-diamond-shapes-have-a-bow-tie)
  Four published lists of bow-tie shapes, the criterion behind them, and why the marquise is hardest but not doomed.
3. 3 · Video
  ## [Bow-tie in the stone, sometimes on your finger: tilt and head shadow](https://digitalgemology.com/learn/bow-tie/bow-tie-tilt-and-head-shadow)
  Why the same stone shows a bow-tie in one room and not in another, and what tilt and your head's shadow do.
4. 4 · Article
  ## [What causes a bow-tie? Four explanations, tested](https://digitalgemology.com/learn/bow-tie/what-causes-a-bow-tie)
  GIA, the NDC, Estate Diamond Jewelry and Ritani explain the bow-tie in different ways. We test each on the light map.
5. 5 · Article
  ## [Is a bow-tie always there? How much is normal](https://digitalgemology.com/learn/bow-tie/is-a-bow-tie-always-present)
  Some bow-tie is "always present", sources say. One counterexample, stress-tested in every room, head shadow and tilt.
6. 6 · Article
  ## [Bow-ties and grading reports: what the numbers can't tell you](https://digitalgemology.com/learn/bow-tie/bow-tie-and-the-grading-report)
  What the report, the finish grades, the ratio and the depth can and can't tell you about a bow-tie.
7. 7 · Article
  ## [Why bow-ties are still cut: weight, outline and cost](https://digitalgemology.com/learn/bow-tie/why-cutters-leave-a-bow-tie)
  The weight trade-off behind a deep-bellied bow-tie: the same carats for less face-up size.
8. 8 · Animated explainer
  ## [Fixing a bow-tie: the steep belly of DG-Bowtie](https://digitalgemology.com/learn/bow-tie/how-to-fix-a-bow-tie)
  The diagnosis and rebuild of a real marquise: the 51.9° belly limit, the result in every tool, and what the fix cost.
9. 9 · Article
  ## [How to check a stone for a bow-tie: a bench routine](https://digitalgemology.com/learn/bow-tie/how-to-check-a-diamond-for-a-bow-tie)
  A routine to check any elongated stone for a bow-tie, from a dim room to its cutting file.

## Cuts in this topic

We sell the files of these cuts: 3D models and cutting files, with a personal-use license.

- [DG-Bowtie Cut](https://digitalgemology.com/cuts/dg-bowtie): 3D files and cutting files, €9.99 each
- [Marquise Cut](https://digitalgemology.com/cuts/marquise): 3D files and cutting files, €9.99 each
- [Oval Cut](https://digitalgemology.com/cuts/oval): 3D files and cutting files, €9.99 each
- [Pear Cut](https://digitalgemology.com/cuts/pear): 3D files and cutting files, €9.99 each
- [Teardrop Cut](https://digitalgemology.com/cuts/teardrop): 3D files and cutting files, €9.99 each

[All topics](https://digitalgemology.com/learn)