Fancy Shapes

In trade practice, everything that is not a standard round brilliant is often grouped under the term fancy shape. This category is useful but extremely heterogeneous. An oval, pear, marquise, cushion, princess, emerald cut, and heart do not have the same outline, facet architecture, or optical challenges.

The greatest mistake is therefore to impose one “ideal” set of proportions or round-brilliant logic on every fancy shape.

Shape, Faceting Style, and Cut Quality

It is necessary to distinguish among:

• shape—the external outline in the face-up view;
• cutting style/facet arrangement—the organization of facets;
• cut quality—how successfully a particular execution achieves its aesthetic, optical, structural, and manufacturing objectives.

A cushion can be brilliant or modified brilliant. A rectangular diamond can be an emerald-style step cut or a radiant-style mixed/brilliant construction. The name of the shape alone therefore does not say enough about optical behavior.

There Is No Single Universal GIA Fancy Cut Grade

As of the factual cutoff of August 8, 2026, GIA assigns an overall Cut Grade on standard natural D–Z grading reports only to the standard round brilliant. Fancy shapes receive separate information such as polish and symmetry, but not one general GIA fancy cut grade comparable to the round brilliant’s Excellent–Poor scale.

This does not mean that fancy-cut quality cannot be measured or analyzed professionally. It means that a laboratory grade must not be invented where the specific service does not issue one.

GIA research from 2024–2026 emphasizes precisely the complexity of evaluating oval, pear, and marquise shapes, including outline appeal, pattern, and behavior in motion.

AGS Ideal as a Specific Exception

The AGS Ideal® Report by GIA is available only for certain qualifying shape/facet-arrangement combinations. In addition to round stones, GIA currently lists specified arrangements among cushion, oval, emerald, square emerald, cut-cornered rectangle/square, modified triangle, decagon, rectangle, square, and other categories as eligible.

The word eligible must be understood literally. The same external outline does not mean that every facet arrangement can receive this supplemental report.

AGS Ideal is therefore not evidence that a universal GIA fancy cut grade has been introduced.

A Shared Framework for Evaluating Fancy Shapes

Regardless of shape, it is useful to ask seven questions:

1. Is the outline harmonious for the intended design?
2. How are light and dark areas distributed?
3. Is there pronounced windowing or undesirable extinction of large areas?
4. How does the pattern change as the stone and observer move?
5. Is the face-up size reasonable relative to the weight?
6. Are there points, corners, or very thin girdle areas with increased mechanical risk?
7. Are polish and symmetry executed to a level appropriate for the stone’s value?

This framework is more useful than one table of “ideal” percentages.

[VISUAL 22.1: Fancy-shape evaluation—outline → pattern → motion → windowing/bow tie → face-up size → durability → finish]

Length-to-Width Ratio Is Not a Grade

Length-to-width ratio strongly changes the impression of ovals, pears, marquises, cushions, and rectangular cuts. But the preferred ratio depends on:

• design;
• size;
• facet arrangement;
• intended use in jewelry;
• personal taste.

A trade range can help with initial filtering, but it is not a laboratory law. Two ovals with the same ratio can have completely different shoulders, bow ties, depths, and virtual-facet patterns.

Oval

For an oval, examine:

• the harmony of its curvature;
• the symmetry of its two halves;
• length-to-width ratio;
• distribution of brightness and contrast;
• the bow-tie zone;
• face-up size;
• behavior when tilted.

The bow-tie effect is not a binary defect. Moderate contrast through the center can give structure to the pattern. A problem arises when the zone remains excessively dark, wide, and visually dominant over a broad range of positions.

Pear

A pear combines a rounded end with one point. The following are evaluated:

• the axis of symmetry;
• the shoulders;
• the shape of the rounded end;
• centering of the point;
• bow tie;
• protection of the point.

A very thin point or an inclusion immediately adjacent to a vulnerable area can be more important in practice than a small difference in the nominal length-to-width ratio.

Marquise

A marquise has two points and a long axis. Its large face-up area can make it appear larger at the same weight, but an excessively shallow or poorly faceted execution can develop windowing or an unpleasant bow tie.

Check:

• whether the points align with one another;
• whether the side curves are harmonious;
• whether there is obvious asymmetry;
• whether both points will be structurally protected in the intended setting.

Cushion

The name cushion covers a broad family of stones: nearly square or elongated, with softer or more tightly rounded outlines and various brilliant and modified brilliant arrangements.

The cushion therefore demonstrates particularly clearly why a table of proportions alone is not enough. Two stones with similar dimensions can have:

• large, clearly legible virtual facets;
• a very fine “crushed-ice” pattern;
• pronounced central contrast;
• different distributions of weight in the pavilion.

Crushed ice should be described as an optical texture, not automatically as a good or bad cut category.

Princess

A princess is most often a square or slightly rectangular modified brilliant with sharp corners. The number of chevrons and the arrangement of pavilion facets change the size and density of virtual facets.

All four corners are important to durability. Their risk depends on:

• material thickness;
• inclusions;
• girdle condition;
• the method of setting.

Evaluation must not be reduced to “which number of chevrons is best.”

Emerald and Square Emerald / Asscher-Style

An emerald cut uses step architecture. Instead of very fine scintillation, it is expected to display a clearer rhythm of broad light and dark zones.

Particularly important in evaluation are:

• the balance of step facets;
• central windowing;
• excessive areas of extinction;
• centering of the keel line;
• clarity and transparency, because internal features are often more readily visible.

The name Asscher may have a historical, descriptive, or branded meaning. A protected trade name should not be used as a generic synonym if the specific product is not entitled to use it.

Radiant

A radiant combines cut corners with brilliant/mixed faceting. It can display a wide range of patterns—from more structured arrangements to finer “crushed-ice” zones.

For fancy-color diamonds, the radiant may also be selected to retain or intensify perceived color. This does not mean that every radiant is “better for color”; the outcome depends on the entire geometry and material.

Heart

A heart requires harmony among:

• the two upper lobes;
• the central cleft;
• the shoulders;
• the lower point;
• the axis of symmetry.

In very small stones, the shape may lose visual legibility. In larger stones, poor geometry can create uneven contrast or a heavy, squat outline.

Trillion, Baguette, and Other Shapes

Trillions and related triangular brilliant/mixed cuts require evaluation of their points, side angles, and central pattern. Baguettes and tapered baguettes, especially as side stones, require very careful matching of dimensions, proportions, and tone because they are often used in pairs or series.

Kite, shield, briolette, rose, and other nonstandard shapes should be evaluated according to the intent of the design rather than forcibly compared with a round brilliant.

A detailed atlas of outlines and variants belongs in Appendix H.

Polish and Symmetry Are Not Decorative Entries

For fancy shapes, polish and symmetry are often the only formal cut-related grades on a standard grading report. They should be taken seriously, but not turned into a complete fancy cut grade.

Excellent symmetry does not guarantee:

• a good outline;
• a desirable bow tie;
• minimal windowing;
• a large face-up area;
• a personally appealing pattern.

A Photograph Is Not Enough

Fancy diamonds are particularly sensitive to:

• camera angle;
• lighting;
• background;
• exposure;
• distance;
• the moment captured from a video.

A static photograph can conceal bow tie or windowing, but it can also exaggerate them. Standardized video, multiple lighting environments, and a physical examination when possible are useful for serious comparison.

Practical Selection Protocol

1. confirm the shape and facet arrangement on the report;
2. check the dimensions and length-to-width ratio;
3. evaluate the outline, not only the number;
4. examine face-up size relative to weight;
5. inspect bow tie, windowing, extinction, and pattern in motion;
6. check polish and symmetry;
7. examine points, corners, girdle areas, and inclusions that pose durability risks;
8. compare multiple stones under similar conditions;
9. do not use a seller’s “ideal ratio” chart as a laboratory standard;
10. separate personal preference from measurable manufacturing quality.

[VISUAL 22.2: Oval, pear, marquise, cushion, princess, emerald, radiant, and heart—outline plus typical optical risk only, with no “ideal ratio” numbers]

Chapter Summary

• Fancy shape is a broad category, not one optical system.
• Shape, facet arrangement, and cut quality are different concepts.
• GIA does not issue a universal overall cut grade for fancy shapes on a standard natural D–Z report.
• The AGS Ideal® Report by GIA is available only for certain qualifying arrangements.
• Length-to-width ratio describes geometry, not overall quality.
• The bow-tie effect is a continuous optical phenomenon, not an automatic defect.
• Crushed ice describes pattern texture, not a grading category.
• An emerald/step cut should be evaluated differently from brilliant architecture.
• The pointed tips of pears, marquises, princess cuts, and hearts require special attention to durability.
• Excellent symmetry does not guarantee a good outline or desirable light performance.
• A static photograph is not enough for a serious evaluation of a fancy-shaped stone.
• Detailed shape variants and trade names are more appropriate for an atlas than for the main text.