Emerald cut
A rectangular step-cut diamond with cropped corners and long parallel facets. Serene and architectural where brilliants are lively — the "hall-of-mirrors" effect is its signature.
The emerald cut is a step cut: instead of the triangular and kite-shaped facets of a brilliant, it uses long rectangular facets arranged in parallel rows on both crown and pavilion. This gives the stone a calm, glassy appearance rather than the scintillating sparkle of a round or oval.
Its defining optical feature is the hall-of-mirrors effect — the long step facets reflect each other in elongated rectangular flashes, creating a sense of depth and serenity. The open table also acts as a window into the diamond, which means clarity is far more visible than in any brilliant cut. Buyers of emerald cuts typically choose VS1 or better.
The shape was originally developed for cutting emerald gemstones — which are brittle — as the step cut reduced the risk of chipping during cutting. Adapted to diamonds, it became a fixture of Art Deco jewellery in the 1920s and has remained a mark of understated sophistication ever since.
- STYLE
- Step cut
- IDEAL L:W
- 1.40–1.50
- CLARITY
- VS1+ recommended
Well-proportioned
The classic emerald cut sweet spot. Long, even step lines, good depth for the hall-of-mirrors effect, and a length-to-width ratio that reads as distinctly rectangular without looking thin.
Ideal L:W 1.40–1.50. Depth 60–65%. Table 60–70%. The long lines of the steps should be crisp and parallel.
Square (Asscher-like)
A square or near-square emerald cut. Sometimes called a "square emerald" to distinguish it from an Asscher, which has deeper cropped corners and a different facet arrangement. Reads more compact and jewel-like.
L:W 1.00–1.10. More compact face-up appearance. Less elongating than a classic rectangular emerald.
Elongated
A more elongated emerald cut. The long parallel facets become very pronounced, and the finger-lengthening effect is maximised. Requires careful evaluation — very elongated stones can show an uneven step pattern.
L:W 1.55–1.80. Visually elongates the finger. Watch for uneven or tapering step lines at the narrow ends.
Step cut vs Brilliant cut
Two fundamentally different approaches to diamond faceting — one maximises sparkle, the other maximises depth.
Calm & architectural
- Long parallel rectangular facets on crown and pavilion
- Hall-of-mirrors: elongated reflections of depth
- Large open table — clarity visible easily
- VS1+ recommended; inclusions not hidden
- Colour shows more — step up one grade vs round
- Art Deco, sophisticated, understated
Lively & scintillating
- Triangular and kite-shaped facets radiating from centre
- Scintillation: hundreds of tiny light flashes
- Facets break up inclusions — hides clarity imperfections
- SI1–VS2 range is typically eye-clean
- Colour hidden better — can go one grade lower vs emerald
- Dynamic, maximum sparkle, versatile
Proportions to look for
GIA does not issue cut grades for emerald cuts. Proportions must be evaluated using depth %, table %, and length-to-width ratio. The most important visual quality — the evenness and richness of the step reflections — can only be assessed by looking at the stone.
Beyond the numbers, look for even, parallel step lines with no "dead zones" (dark areas) and a clear, deep hall-of-mirrors from crown to pavilion. This cannot be read from a certificate.
Clarity and colour in an emerald cut
CLARITY
Visibility is everything
The open table of an emerald cut is the most revealing of any shape. What is invisible in a round VS2 may be clearly apparent in an emerald VS2. The step facets act like windows — they don't break light into small flashes that hide inclusions, they let you see straight in.
COLOUR
Step up one grade
The emerald cut's large flat facets allow the body colour of the diamond to show through more than a brilliant cut. The same colour grade reads warmer in an emerald than in a round — typically by one full grade. A round G appears near-colourless; an emerald G may show a warm tint.
Round brilliant
Emerald cut equivalent look
To achieve the same visual colour appearance, step up approximately one grade vs a round brilliant.
History & setting
The step cut originated with coloured stones — emeralds, rubies and sapphires — where the parallel facets reduced polishing stress on brittle crystals. Applied to diamonds in the early 20th century, it became the defining shape of Art Deco jewellery: geometric, linear, architectural.
The emerald cut fell out of fashion during the mid-20th century as round brilliants dominated. Its revival in the 2010s was driven by a preference for understated, sophisticated jewellery over maximum sparkle — often paired with tapered baguette side stones that reinforce the linear aesthetic.
Three-stone with baguettes
The classic pairing — two tapered baguette side stones mirror the emerald's step-cut geometry. The linear aesthetic of all three stones is unified.
Solitaire, thin band
A simple platinum or gold band lets the emerald cut's open table and proportions speak for themselves. No distractions from the stone's geometry.
East-west setting
Rotating the stone 90° so it sits horizontally on the finger. A contemporary choice that emphasises the long axis across the finger rather than along it.
Halo (rare)
A rectangular halo of small diamonds around the emerald. Less common than with ovals — the halo can break up the clean step-cut geometry.
Questions about emerald cut
Why does the emerald cut show inclusions more than a round brilliant?
The emerald cut's large, open table and long parallel step facets act like a window into the stone. Rather than breaking up reflections into dozens of tiny flashes as a brilliant cut does, the step cut lets you see deeply and clearly into the diamond. Inclusions that would be invisible in a VS2 round can be clearly visible in a VS2 emerald. Most buyers of emerald cuts step up to VS1 or VS2 as a minimum, and many choose VVS2 or better for stones above 2 ct.
What is the hall-of-mirrors effect?
The hall-of-mirrors (or "ice rink") effect is the optical signature of a well-cut emerald cut. The long parallel step facets act as mirrors, reflecting each other in a series of elongated, rectangular flashes. The result is a calm, architectural beauty rather than the scintillating sparkle of a brilliant cut. The depth of the reflections and their evenness across the stone are the primary quality indicators for an emerald cut.
What is the ideal length-to-width ratio for an emerald cut?
The classic range is 1.40–1.50. At this ratio the stone reads as distinctly rectangular without looking thin. Some buyers prefer a more square stone (1.10–1.20, sometimes called a "square emerald") or a more elongated look (1.55–1.75). The choice is personal, but very elongated emerald cuts (above 1.70) can show uneven step patterns at the narrow ends — something to assess in person or from a clear video.
Does the emerald cut look smaller than a round of the same carat weight?
Yes, typically. An emerald cut's depth is proportionally greater than a round brilliant, which means more weight is carried below the girdle. A 1.00 ct round is approximately 6.4–6.5 mm in diameter; a 1.00 ct emerald cut is approximately 6.8–7.0 × 4.7–5.0 mm — less face-up area overall. Buyers who want a larger face-up appearance often choose an oval or a longer emerald cut.
What depth % should I look for in an emerald cut?
The typical good range is 60–68%. Shallower emerald cuts (below 60%) can appear watery or "glassy" without the rich step reflections. Deeper cuts (above 70%) hide weight in the pavilion and look smaller face-up. A depth of 61–66% is generally a good target. Table % is also important — 60–70% is typical, though what matters more is the evenness and parallel alignment of the step facets rather than the table % alone.
Is the emerald cut the same as the Asscher cut?
No. Both are step cuts, but an Asscher cut is square with more deeply cropped corners, giving it an octagonal face-up outline that produces a more pronounced "windmill" or cross-shaped optical pattern. The emerald cut is typically rectangular (L:W 1.35–1.65) with shallower crops. The Asscher was developed by Joseph Asscher in 1902; the modern square emerald is sometimes called a "square emerald" to avoid confusion. They share the step-cut aesthetic but have distinct proportions and optical signatures.