Diamond shapes
A diamond's shape is the outline you see from above. Round is the classic and the most popular. The other shapes, such as oval, cushion, princess and heart, are called fancy shapes.
- A round brilliant has 57 or 58 facets, laid out to send light back to your eye.
- Shape and cut are different things: shape is the outline, cut is how well the facets are made.
- In RXXO the heart is the rarest shape.
All 10 shapes, rarest first
Odds in RXXO- HeartNeeds careful symmetry, and at least half a carat to show its shape well.1 in 100
- PearA teardrop: round at one end, pointed at the other.1 in 20
- MarquiseLong, with two pointed ends. Also called navette.1 in 20
- RadiantAn emerald's outline with a brilliant's sparkle and cropped corners.1 in 13
- TrillionA three-sided brilliant.1 in 11
- PrincessA square brilliant with sharp corners.1 in 10
- EmeraldA step cut with long, open facets, like a hall of mirrors.1 in 10
- CushionSoft, rounded corners and a pillow shape.1 in 10
- OvalA stretched round. It can look bigger for its weight.1 in 8
- RoundThe classic, known for the most brightness of any cut.1 in 3
In RXXO
In RXXO, 1 in 3 diamonds is round. Hearts are the rarest, 1 in 100.
Heart-shaped RXXO diamonds
Look closer
Inside a round brilliant
On top sits the table, the largest facet. Around it, the crown has 8 bezels, 8 stars and 16 upper halves. Below, the pavilion has 16 lower halves, 8 mains and, sometimes, a tiny culet at the point.
Why round took over
Round diamonds were cut before 1750, but they were hard to make. In 1873 Henry Morse, a Boston cutter, invented the bruting machine, which made round stones far easier to cut. Before that, cutters followed the rough crystal and often ended up with cushion-like shapes.
Today
The round brilliant is still the favourite, at nearly a third of all engagement ring diamonds.
Questions
What is the most popular diamond shape?
Round. The round brilliant makes up nearly a third of engagement ring diamonds, and is known for the most brightness of any cut.
How many facets does a round diamond have?
57 or 58. The 58th is the culet, a tiny facet at the bottom point that some stones do not have.
What is the difference between shape and cut?
Shape is the outline, such as oval or pear. Cut is the whole design and how well it is made: the facets, their angles and their finish.
What is a fancy shape diamond?
Any shape other than round: oval, cushion, princess, emerald, pear, marquise, heart, radiant, trillion and others.
Which diamond shapes look bigger?
Oval and marquise can look bigger than other shapes of the same carat weight.
What is the rarest diamond shape in RXXO?
The heart, 1 in 100. Round is the most common, 1 in 3.
RXXO numbers are the odds every mint draws from. Updated 8 October 2026.