Diamond Shapes Guide: Round, Pear, Oval, Radiant, Emerald and More

People use "shape" and "cut" as if they mean the same thing. They do not. Shape is the outline you see from above: round, pear, oval. Cut is how well the facets are proportioned and finished, and it decides how much light comes back to your eye. A pear can be cut beautifully or badly. Our diamond cut guide covers the quality side; this page is about the outline.

Shapes also fall into two faceting families:

• Brilliant cuts (round, oval, pear, marquise, heart, cushion, radiant) use triangular and kite-shaped facets that break light into sparkle.
• Step cuts (emerald, Asscher, baguette) use long parallel facets that look like a staircase or a hall of mirrors.

The table below compares the shapes you will see most in engagement rings. The last two columns come from our own house inventory of 84 rings, all graded E color, VS1 clarity.

Shape	Faceting	Looks per carat	Hides inclusions	House rings	House price range
Round	Brilliant	Baseline	Very well	21 lab, 5 natural	$960 to $6,000
Oval	Brilliant	Larger	Well	10 lab, 1 natural	$1,500 to $5,200
Pear	Brilliant	Larger	Well	8 lab	$2,800 to $5,300
Emerald	Step	Larger on top, flatter sparkle	Less well	8 lab, 1 natural	$1,700 to $8,900
Radiant	Brilliant	Similar to slightly larger	Well	6 lab	$2,200 to $4,500
Marquise	Brilliant	Largest for its weight	Well	5 lab	$1,050 to $8,500
Heart	Brilliant	Similar	Well	8 lab	$1,800 to $5,200
Cushion	Brilliant	Similar to slightly smaller	Well	2 lab	$1,200 to $3,800

"Looks per carat" is a general rule from how weight spreads across the top of each shape, not a lab grade. Depth matters too: a deep stone of any shape hides weight underneath.

The round brilliant has 57 or 58 facets arranged to return as much light as possible. It is the only shape that gets an overall cut grade on a GIA natural report, because its ideal proportions are so well studied. A well-cut 1 carat round measures about 6.5 mm across.

Round costs more per carat than most fancy shapes, mostly because more of the rough crystal is cut away to make it. Example from our showroom: Round Lab Diamond Ring 3.96 ct, 14K White Gold at $5,400.

Round is also the easiest shape for comparing lab-grown and natural side by side, because so many of each exist. In our house collection, the Round Lab Diamond Ring 4.62 ct, 14K Yellow Gold is $2,800, while the Round Natural Diamond Ring 4.25 ct, 14K Yellow Gold is $6,000. Similar size and grade, different origin, more than double the price.

These three stretch a brilliant cut along one axis. That stretch spreads weight across more surface, so they look larger than a round of the same carat and make fingers look longer. All three can show a bow-tie, a dark band across the middle where light leaks out. A good cut keeps it small.

• Oval: soft and even, no point to protect. See the oval cut guide.
• Pear: a teardrop, one round end and one point. See the pear cut guide.
• Marquise: two points, the longest look of any shape. Example: Marquise Lab Diamond Ring 7.04 ct, 14K White Gold at $8,500.

Check the bow-tie in person or on video, never from a single still photo. A still can hide it or exaggerate it depending on the light. Tilt the stone slowly; a bow-tie that flickers is fine, one that stays black is not.

Emerald and radiant can share the same rectangular outline with clipped corners, but they behave very differently.

The emerald cut is a step cut. Its long, open facets give broad flashes of light instead of sparkle, and they show inclusions and color more easily. That is why buyers often choose a higher clarity for emerald cuts. The emerald cut guide covers it in depth.

The radiant cut uses brilliant faceting inside the same rectangle, so it sparkles like a round and hides small inclusions well. If you like the shape of an emerald but want more fire, the radiant is the usual answer. More in the radiant cut guide. Example: Radiant Lab Diamond Ring 7.98 ct, 14K Yellow Gold with a 4.01 ct center, $4,400.

Heart shapes need a well-defined cleft and two even lobes; below about 1 carat the outline gets harder to read once prongs cover the edges. The heart rings in our house collection that list a weight run from 2 to 3.14 carats total, such as the Heart Lab Diamond Ring 3.14 ct, 14K White Gold at $3,900 with a 2.50 ct center.

Cushion cuts are square to slightly rectangular with rounded corners and large facets that give chunky flashes of light. Princess cuts are square brilliants with sharp corners that need protection. Asscher cuts are square step cuts, an emerald cut's square cousin.

Face-up size is what people notice on a hand, and shape changes it more than most buyers expect. A rough ranking for stones of the same weight and normal depth, from largest-looking to smallest-looking:

1. Marquise
2. Pear and oval
3. Emerald (wide table, but less sparkle to catch the eye)
4. Radiant and heart
5. Round
6. Cushion and princess

For reference, published size charts put a 1 carat oval at about 7.7 x 5.7 mm and a 1 carat pear at about 8.5 x 5.5 mm, against roughly 6.5 mm for a round. Exact sizes vary with each stone's depth. See how real carat weights look in our guide to 2 to 5 carat diamonds on the hand.

Depth is the hidden variable. Two 2 carat ovals can look different sizes because one carries more weight below the girdle. Divide the depth by the width from the report: stones in a normal range face up their full size, while very deep ones look small for their weight. When a stone seems like a bargain for its carat, check the depth first.

Setting matters too. A halo adds a border of sparkle around the center stone, and a slim band makes the center look larger by contrast. Shape, depth and setting together decide how big a ring looks across the table.

Some shapes need specific protection, and some settings suit one shape better than another. Plan the two together.

Shape	Weak spot	Common setting choice
Round	None in particular	Four or six prongs, any profile
Oval	None in particular	Four or six prongs; prongs at the ends help the outline
Pear	The single point	V-prong at the tip, or a bezel
Marquise	Both points	Two V-prongs, one at each tip
Princess	Four sharp corners	V-prongs or corner claws
Emerald and radiant	Corners, protected by the trim	Four corner prongs or double claws
Heart	The point and the cleft	V-prong at the point, prong at the cleft

The setting also changes the look. A halo of small diamonds makes any shape read larger. A thin band makes the center stone look bigger by contrast. Our solitaire setting guide covers prongs and profile in detail.

Two more choices change how a shape reads once it is on a finger.

Metal color. Shapes that hold more color at the ends, such as pear, oval and marquise, can pick up a faint warm tint at the tips in yellow gold. With an E color stone like those in our house rings, that effect is minimal. White gold and platinum keep the look icy. Yellow gold warms the whole ring and can mask a faint tint in a near-colorless stone.

Finger and hand. As a loose guide:

• Short or wide fingers: elongated shapes such as oval, pear and marquise add length.
• Long, slim fingers: round, cushion and radiant balance the length; a long emerald looks elegant.
• Very active hands: rounded outlines like oval and round avoid exposed points.

These are tendencies, not rules. The best test is trying shapes on, which is why we keep different outlines and weights in the showroom.

1. Collect pictures of rings the wearer has saved or admired. Most people already lean toward one outline.
2. Decide sparkle or flash. Brilliant shapes sparkle; step cuts give broad flashes. That one choice removes half the options.
3. Pick a ratio if the shape is elongated. Fuller or slimmer changes the look as much as the shape does.
4. Then set the carat and grades. With the shape fixed, compare stones within it, using the same lab report type.

When you are ready to look at real pieces, start with the full rings collection or jump straight to 2 carat engagement rings.

Brilliant shapes scatter light and hide small inclusions; step cuts put them on display. That gives a simple buying rule:

Shape family	Clarity most buyers find eye-clean
Round, oval, pear, marquise, heart, radiant, cushion	VS2 and up in most stones; some SI1
Emerald, Asscher, baguette	VS1 and up

Our house rings are all graded VS1, so every shape on this page sits in the eye-clean zone. Browse them by shape on the lab diamond engagement rings page, or start with pear, oval and emerald.