Shape · Chapter 09

Fancy shapes: what the report can’t show

Bow-ties, windows, ratios, and points—the appearance questions a fancy shape leaves to your own eye, one shape at a time.

A fancy-shape report can be excellent on every line and still describe a stone you would not choose. The paper records the outline; the pattern is something you have to watch move.

The report records the outline, not the pattern

For most fancy shapes a laboratory reports measurements, table, depth, girdle, culet, polish, and symmetry, but no overall cut grade and no crown or pavilion angles. Polish and symmetry describe finish—how smooth the facets are and how precisely they meet—not how light travels through the stone. That is why a fancy shape with excellent finish grades can still show a heavy bow-tie, a window, or a dull patch. The numbers set a starting range; the face-up pattern decides.

Worth remembering: Strong finish grades and a weak face-up pattern can belong to the same stone.

Bow-ties: normal, and when they are not

A bow-tie is a darker band running across the width of an elongated brilliant—most often an oval, pear, or marquise, and sometimes an elongated cushion or radiant. Some contrast across the middle is part of how these shapes are cut, and a stone with none at all can look flat. The useful test is movement: in a slow tilt, a normal bow-tie flickers, breaks up, and returns. A problem bow-tie stays as a fixed dark band from a normal viewing distance in ordinary light, and draws the eye before the sparkle does. Judge it face-up and straight overhead; a video shot at an angle can hide a bow-tie or exaggerate one.

Worth remembering: A bow-tie that flickers is character. One that stays put is the thing to weigh.

Length-to-width ratio is taste, not performance

Divide the length by the width from the report’s measurements to find the ratio. It describes the outline—slender or full, long or round-shouldered—and preferred ranges differ from buyer to buyer. It does not predict brightness, and it does not guarantee face-up size. Two ovals of the same weight and ratio can spread very differently if one carries more depth. Choose the ratio by how the outline looks on the hand, then compare millimeters and pattern within it.

Pears and marquises: the point, the shoulders, the middle

Beyond the bow-tie, look for a see-through or washed-out area toward the point, and for shoulders and wings that curve evenly on both sides of the long axis. The point is the most exposed part of the stone and is best held by a V-prong or bezel. A marquise has two such points; a pear has one, plus a rounded end where the outline should look full rather than flattened.

Princess cuts: more than table and depth

A princess report rarely gives the angles that shape its pattern, and many princess cuts carry a good deal of depth, so check the millimeters against the weight to see how large the stone faces up. Face-up, look for an even spread of sparkle across all four quadrants, without dark corners or a dim central cross that stays fixed as the stone moves. The four sharp corners are its weak points and are usually protected by V-prongs.

Emerald and Asscher cuts: windows and the open table

Step cuts trade scattered sparkle for broad, slow flashes of light and dark. A window is a washed-out, see-through area in the center where light passes through instead of reflecting back—often a sign of a shallow pavilion, and easiest to see against a patterned background or on the hand. A good step cut shows crisp steps receding toward the center as it tilts. The same open facets that make a step cut calm also show inclusions more plainly than a brilliant does, so a clarity grade that would stay hidden in a round may be visible here.

Worth remembering: In a step cut, look through the table as well as at it.

Radiants: brilliance in a cornered outline

A radiant pairs the square or rectangular outline of a step cut with brilliant faceting, and its trimmed corners are less exposed than the sharp corners of a princess. Many radiants return a fine, crushed-ice sparkle, and many carry considerable depth, so check the millimeters against the weight to see how large the stone faces up. Elongated radiants can show a bow-tie; some square radiants show a dark center that stays put as the stone tilts.

Hearts: balance and the cleft

A heart depends on balance: two lobes of matching size and curve, a clearly defined cleft, and a point centered below it. Small hearts can lose their outline once set, so the shape reads most clearly in larger sizes. Hearts can show a bow-tie across the width, and the point needs the same protection as a pear’s.

Cushions: chunky or crushed

Cushions vary more than their name suggests. Some return broad, chunky flashes; others a fine, crushed-ice sparkle that can blur the facet pattern and make the stone look slightly hazy. Neither is a defect, but they look very different on the hand, and the report does not say which one you have. Elongated cushions can also show a bow-tie.

Ask for the video that answers these questions

Request a face-up video taken straight overhead, a slow tilt side to side and end to end, and a view against a plain white background under even, daylight-like light. Ask the seller to show the girdle inscription or the report number in the same session so you know it is the same stone. Bright spotlights and dark backgrounds flatter every diamond; they tell you little about bow-tie, windowing, or haze.

Worth remembering: The right video is worth more than another decimal on the report.

Essential language

Bow-tie: A darker band across the width of an elongated brilliant, where facets return less light toward the viewer.
Window: A washed-out, see-through area where light passes through the stone instead of reflecting back.
Length-to-width ratio: Length divided by width; a description of outline, not of light performance.
Spread: How large a diamond faces up for its weight.
Step cut: A cutting style with long, parallel facets arranged like steps, as in emerald and Asscher cuts.
Cleft: The notch between the two lobes of a heart shape.

Questions to take with you

Does the bow-tie flicker as the stone tilts, or stay as a fixed dark band?
Is the video face-up and straight overhead, in even light, against a plain background?
Is there a see-through area in the center or toward the point?
How large does the stone face up in millimeters for its weight?
Will the points or corners be protected by the setting?
Was the report number or inscription shown in the same video session?