Diamond Shape vs. Cut Style

This distinction is important enough to repeat.

Shape describes the outline.

Cut style describes the arrangement of facets.

A diamond may be oval in shape and brilliant in cutting style.

An emerald-cut diamond is rectangular in shape with a step-cut facet pattern.

GIA identifies two of the most important facet families as brilliant cuts and step cuts.

Brilliant Cuts

Brilliant cuts use numerous triangular and kite-shaped facets to create strong light return, fire, and scintillation.

Examples include:

• Round brilliant
• Oval
• Pear
• Marquise
• Princess
• Many cushion cuts
• Radiant

Step Cuts

Step cuts use long, broad facets arranged in a layered pattern.

They create a calmer, more architectural appearance often described as a hall-of-mirrors effect.

Examples include:

• Emerald cut
• Asscher cut

They generally show inclusions and body color more readily than brilliant cuts.

Understanding the Major Diamond Shapes

Round Brilliant

The round brilliant is the benchmark of modern diamond cutting and remains the most recognized diamond shape.

A standard round brilliant has 57 or 58 facets, depending on whether a culet is present.

Why People Choose It

• Maximum emphasis on brilliance
• Highly standardized cut evaluation
• Extremely versatile
• Works in almost every setting
• Excellent light performance when well cut

What to Watch

Because round diamonds are so standardized, proportion and cut quality matter enormously.

For most buyers, I would rather sacrifice a little color or clarity than sacrifice cut quality in a round brilliant.

Oval Cut

Oval diamonds combine the sparkle of a brilliant cut with an elongated silhouette.

They have become extremely popular because they often appear larger face-up than round diamonds of similar carat weight.

Advantages

• Elongates the finger
• Strong brilliance
• Large visual spread
• Works in solitaires, halos, three-stone rings, and eternity bands
• Modern but still classic

What to Watch: Bow Tie

Many elongated brilliant cuts can show a darker area through the center called a bow tie.

Some bow tie is normal.

The problem is when it becomes dark, heavy, or visually distracting.

This cannot be judged reliably from a grading report alone.

You need to see the diamond.

Length-to-Width Ratio

Oval shape preference is highly personal.

A shorter oval appears fuller.

A longer oval appears more dramatic and slender.

There is no single “correctâ€� ratio.

Pear Shape

The pear combines characteristics of a round brilliant and marquise.

One end is rounded while the other tapers to a point.

Why People Love It

• Distinctive silhouette
• Elegant and dramatic
• Can make the finger appear longer
• Beautiful in pendants as well as rings

What to Watch

• Bow tie
• Symmetry of the shoulders
• Proper alignment of the point
• Protection of the pointed end

The point should generally be protected by an appropriate prong.

Marquise

The marquise is elongated with pointed ends.

Because of its long shape, it can offer exceptional face-up spread for its carat weight.

Advantages

• Appears large
• Dramatically elongates the finger
• Very distinctive
• Excellent for vintage-inspired designs

What to Watch

• Bow tie
• Symmetry
• Properly aligned points
• Durability at the tips

Emerald Cut

Emerald cuts are completely different in personality from brilliant cuts.

Instead of intense scintillation, they feature broad step facets and long flashes of light.

The Look

Elegant.

Clean.

Architectural.

Sophisticated.

The large open table allows you to look deeply into the diamond.

That is precisely why clarity becomes so important.

What to Prioritize

• Clarity
• Attractive proportions
• Symmetry
• Even step pattern
• Pleasant length-to-width ratio
• Minimal windowing or dead areas

An emerald cut is rarely chosen because someone wants the most sparkle possible.

It is chosen because they love the geometry.

Asscher Cut

The Asscher is essentially a square step cut with deeply clipped corners.

It creates a hypnotic, geometric pattern.

Characteristics

• Square outline
• Step facets
• Vintage character
• Strong symmetry
• Deep visual pattern

Like emerald cuts, Asschers tend to reveal inclusions and body color more readily.

Princess Cut

The princess is usually square with pointed corners and a brilliant-style facet arrangement.

Advantages

• Strong sparkle
• Contemporary geometry
• Efficient use of rough diamond
• Often attractive pricing relative to rounds

What to Watch

The pointed corners are vulnerable.

A good setting should protect them.

Radiant Cut

The radiant combines a rectangular or square outline with brilliant-style faceting.

Think of it as some of the geometry of an emerald cut with much more sparkle.

Advantages

• Bright and lively
• Available square or elongated
• Durable clipped corners
• Often hides inclusions well
• Beautiful for larger stones

Radiants can vary tremendously in appearance, so photographs and videos matter more than the name alone.

Cushion Cut

Cushions typically have a square or rectangular outline with rounded corners.

But “cushionâ€� describes a broad family.

Two cushion diamonds can have completely different facet patterns.

Common Looks

• Chunky antique-style facets
• Modern brilliant cushions
• Crushed-ice appearance
• Elongated cushions

This is why simply asking for a “cushion cutâ€� is not enough.

You should decide which kind of cushion appearance you actually like.

Heart Shape

A well-cut heart diamond requires strong symmetry.

Both lobes should balance, and the cleft should be defined without looking overly deep or shallow.

Hearts tend to show their shape more clearly at larger sizes because very small hearts can lose definition.

Antique Diamond Cuts

Not every diamond should look modern.

Older cutting styles have experienced a major resurgence because they offer character that modern precision cutting sometimes intentionally removes.

Old Mine Cut

Old mine cuts generally have:

• Chunky facets
• A squarish cushion outline
• High crowns
• Small tables
• Visible culets
• Strong individual personality

They were cut primarily for candlelight and softer historical lighting.

Old European Cut

Old European cuts are predecessors to the modern round brilliant.

They often feature:

• Small tables
• High crowns
• Deep pavilions
• Large open culets
• Broad flashes of light

These cuts appeal to buyers who want history and personality rather than perfect modern symmetry.