Heart Shaped Diamond

What makes a good heart shaped diamond?

A good heart shaped diamond comes down to three things: it is big enough to read as a heart (about half a carat and up), its two lobes match, and the cut throws light evenly without a heavy dark band through the middle. Get those right and you have one of the most charming stones in the case. Get them wrong and the shape works against you, because the heart shows off a cutter's mistakes more plainly than almost any other shape.

The heart is a modified brilliant cut — essentially a pear with a cleft notched into the rounded end. That cleft, the two lobes, and the point are all extra chances for the cut to go sideways. It is a romantic, distinctive choice, and it asks more of both the cutter and the setting than a round brilliant does. If you want the look of a fancy shape with a calmer cut to manage, an oval or a cushion is more forgiving. But nothing else says what a heart says. For the basics behind the four Cs and how cut is graded, our guide to diamonds is a good starting point.

Go at least half a carat so the shape reads

Size matters more for a heart than for most shapes. Below roughly 0.50 carat the cleft and the two lobes shrink to the point where, set in a ring and seen at arm's length, the outline stops registering as a heart. The GIA makes the same point: it can be hard to perceive the heart in a diamond under half a carat. Buyers who go smaller often end up with a stone that reads as a slightly lopsided round, which defeats the whole reason you chose a heart. Half a carat is the sensible floor. If your budget reaches 0.75 carat or more, the lobes and cleft get crisper and the romance of the shape really lands.

One related tip: hearts can carry their weight a little low, meaning a stone can look smaller face-up than its carat number suggests. Always judge the millimetre measurements and the look of the stone, not just the carat figure on the report.

The ratio: aim for 0.90 to 1.10

Length-to-width ratio is how tall the heart is versus how wide. You get it by dividing the length measurement by the width. The GIA notes that grading reports give the measurements but not the ratio itself, and it does not assign an overall cut grade to fancy shapes, so you work the ratio out from the length and width on the report and judge the cut yourself.

For a heart, the sweet spot is 0.90 to 1.10, and most people land happiest near 1.00. Inside that range you get a plump, balanced heart. Drop much below 0.90 and the stone starts to look squat and wide; climb much above 1.10 and it stretches and narrows, losing the soft round shoulders that make a heart a heart. Ratio is personal, so trust your own eye — but if you are unsure, stay close to 1.00.

Symmetry is the make-or-break

If you remember one thing, make it this: the two lobes must match. Set the stone straight in front of you and check that the left and right halves mirror each other — same width, same height, same roundness. The cleft between them should be a clean, sharp notch sitting dead centre, and the point at the bottom should line up directly under it. A heart that leans, has one fat lobe and one flat one, or has an off-centre cleft will look wrong to people even if they cannot name why. This is the single most common fault in heart diamonds and the easiest to catch with your own eyes. On our bench in Coquitlam, lopsided lobes are the first thing we point out when a customer brings in a heart they are unsure about.

Protect the point with a V-prong

That sharp tip at the bottom is the most vulnerable part of any heart. Diamond is the hardest natural material — it sits at 10, the top of the Mohs hardness scale — but hardness only means it resists scratching. It says nothing about toughness against a knock, and a fine point concentrates any impact. A sharp corner left exposed can chip.

The fix is simple and standard: set the point in a V-shaped prong that wraps around the tip and shields it from both sides. Our on-site goldsmith always finishes a heart this way. It guards the most fragile part of the stone and, as a bonus, keeps the point looking crisp instead of letting a plain prong blunt the outline. If you want to see how settings change the way a stone sits and how protected it is, our guide to engagement ring settings walks through the options.

The bowtie — what it is and how much is too much

A bowtie is a dark, bow-shaped shadow that runs across the centre of a stone. It comes from the way the facets are angled and your own head blocking light as you look down. Elongated brilliant shapes all show it to some degree, and the heart, with its long axis and cleft, is no exception — every heart has a little bowtie.

A faint bowtie that flickers and mostly vanishes as you tilt the stone is completely normal and nothing to worry about. What you avoid is a heavy, fixed dark band that stays dark across the whole middle and kills the sparkle. Grading reports do not measure the bowtie, so this is one you judge with your eyes (or ours) in good light. Tilt the stone, move it under the light, and watch whether the centre comes alive or stays flat.

Setting it all together

Hearts look their best when the setting lets the shape lead: a simple solitaire, a thin halo that echoes the outline, or a three-stone ring with the heart pointing down. Whatever you choose, the V-prong on the point is not optional. If you want to walk through size, ratio and setting options for a specific stone, our engagement ring guide covers how we build a ring around a centre diamond, and our diamond guide for engagement rings goes deeper on choosing the stone itself.

Frequently Asked Questions