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A marquise diamond typically faces up around 10% to 15% larger than a round brilliant of the same carat weight, because its elongated outline spreads weight across the surface. It is also usually priced below a round of matching grades, so the same budget often buys a larger-looking stone.
A marquise diamond is the shape that makes people ask, "How big is that?" It stretches across the finger, flatters the hand and gives more visible size for your carat budget than most shapes. It is also the shape that punishes careless buying, because a poor ratio, a dark bow-tie across the middle or two unprotected tips can turn a bargain into a regret.
This guide shows you how to avoid all three. You will see how much bigger a marquise looks, which millimetre size suits your hand, how to choose the right ratio, which settings protect the points and how to spend less without losing the look. Compare shapes in our diamond shape guide, follow the checklists, and you can shop for a marquise ring with confidence.
Why a Marquise Diamond Looks Bigger Per Carat
A marquise diamond looks bigger per carat because its elongated, shallow cut maximises face-up surface area (spread) rather than hiding weight in the bottom of the stone. Here’s a table showing the industry sizing:
|
Shape (1.00 ct, well cut) |
Face-up area vs round |
Approx. area |
Carat for the same face-up area as a 1.00 ct round |
|
Round brilliant |
Baseline |
About 33 mm² |
1.00 ct |
|
Oval |
Roughly 10% larger |
About 36 mm² |
About 0.85 to 0.90 ct |
|
Marquise |
Up to around 15% larger |
Up to about 38 mm² |
About 0.80 to 0.85 ct |
*These are estimates, and individual stones vary with depth and ratio.
Here’s what you should do instead:
-
Want the look of a 1.00 ct round? Start your search at 0.80 to 0.90 ct marquise.
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Compare millimetres, not carats. Length and width tell you the real size.
-
Check the width too. A long but narrow stone looks slim, not large.
Marquise Diamond Sizes in mm (0.50 to 3.00 ct)
The sizes below assume a 2.0 length-to-width ratio and are scaled from a 1.00 ct stone of about 10 x 5 mm. The ring size column is a starting point, using Australian letters with US numbers.
|
Carat weight |
Approx. length x width (mm) |
What ring sizes it suits |
|
0.50 ct |
7.9 x 4.0 |
K to M (US 5 to 6) |
|
0.75 ct |
9.1 x 4.5 |
K to N (US 5 to 6.5) |
|
1.00 ct |
10.0 x 5.0 |
L to O (US 5.5 to 7) |
|
1.50 ct |
11.4 x 5.7 |
N to Q (US 6.5 to 8) |
|
2.00 ct |
12.6 x 6.3 |
O to R (US 7 to 8.5) |
|
3.00 ct |
14.4 x 7.2 |
P to T (US 7.5 to 9.5) |
A shallow stone measures longer for its weight, so always confirm the measurements on the certificate. Not sure of your size? Use our ring size conversion chart.
Marquise Diamond Prices in Australia (2026)
When comparing diamond engagement rings in Australia, a marquise cut offers exceptional value. Whether exploring lab-grown diamonds or natural diamond engagement rings, a marquise diamond is typically priced significantly below a traditional round brilliant cut of the exact same carat weight, colour, and clarity.
The prices below represent current market averages for popular certified grades (G to H Colour, VS2 to SI1 Clarity, Excellent Symmetry) set in standard gold bands.
|
Carat Weight |
Lab-Grown Marquise Price (AUD) |
Natural Mined Marquise Price (AUD) |
Visual Perceived Size (Spread) |
|
0.50 ct |
$1,100 – $1,600* |
$2,800 – $4,200* |
~8.0 mm × 4.0 mm |
|
0.90 – 0.99 ct |
$1,800 – $2,400* |
$5,500 – $7,800* |
~10.0 mm × 5.0 mm |
|
1.00 ct |
$2,200 – $2,900* |
$7,900 – $11,500* |
$10.2 mm × 5.1 mm |
|
1.50 ct |
$2,600 – $3,400* |
$13,000 – $18,500* |
~11.5 mm × 5.7 mm |
|
2.00 ct |
$2,900 – $4,200* |
$21,000 – $34,000* |
~12.7 mm × 6.3 mm |
|
3.00 ct |
$3,073 – $5,500+* |
$42,000 – $65,000+* |
~14.5 mm × 7.2 mm |
*Inventory changes daily. Live wholesale feed rates fluctuate based on global currency conversion rates.
How to Allocate Your Marquise Budget (Prioritisation Hierarchy)
To get the most beautiful stone for your money, spend your budget in this specific order:
-
First Prioritise - Length-to-Width Ratio and Symmetry: Look for a classic 1.75 to 2.15 ratio. Excellent symmetry prevents the "bow-tie effect" and defines how brilliantly the stone reflects light.
-
Second Prioritise - Carat Weight Optimisation: Use the "under-the-carat" tip outlined above (e.g., buying a 0.90–0.95 ct or a 1.90 ct stone) to bypass artificial price spikes.
-
Last Prioritise - Colour and Clarity: Drop down slightly to eye-clean VS2/SI1 clarity and near-colourless G/H grades. These small grade drops are virtually impossible to notice without a jeweler’s loupe, letting you save thousands.
Length-to-Width Ratio: The Ideal Range
Ratio is length divided by width, and it controls how slim or full the stone looks. This is common industry guidance rather than a fixed standard.
|
Ratio |
Look |
Best for |
|
1.50 to 1.74 |
Fuller, closer to an oval |
Wider fingers or a softer look |
|
1.75 to 1.99 |
Balanced and slightly broad |
Every day wear on most hands |
|
2.00 to 2.25 |
Classic, slender and lengthening |
A dramatic look |
|
Above 2.25 |
Very narrow, with exposed points |
Experienced buyers only |
Check any stone in four steps.
-
Work out the ratio: Divide length by width, for example, 10.0 ÷ 5.0 = 2.0.
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Watch the face-up video: If a dark bow-tie band dominates the centre, skip the stone.
-
Read the certificate: Look for excellent or very good symmetry and polish, with both points aligned.
-
Check colour and clarity: Choose near-colourless or better, with any inclusions away from the tips.
Our diamond cut guide explains what to look for on the certificate.
Best Settings for a Marquise Diamond Ring (and Protecting the Points)
The points chip more easily than the rest of the stone, so choose a setting that covers or cradles them. Diamond marquise engagement rings work best in these styles.
|
Setting |
Point protection |
Look |
Choose it if |
|
Solitaire with V-prongs |
Good, as a V wraps each tip |
Classic and shows the most stone |
You want the traditional look |
|
Excellent |
Sleek and modern |
You have active hands |
|
|
Halo or hidden halo |
Good with V-prongs |
Bigger, sparkly look |
You want an extra size |
|
Good with V-prongs |
Balanced and symbolic |
You want a meaningful design |
Protect the ring with these habits.
-
Ask for V-prongs on both points.
-
Ask for a girdle that is not extremely thin at the tips.
-
Add a curved band. A matching women's wedding band lets the ring sit flush.
-
Insure it. Our jewellery appraisal gives you the document your insurer needs.
-
Check the prongs once a year, and remove the ring for heavy work.
Want something different? Our team offers free custom design around your chosen stone.
Marquise vs Oval vs Pear
|
Feature |
Marquise |
Oval |
Pear |
|
Face-up size vs round |
Up to around 15% larger |
Roughly 10% larger |
Around 15% larger |
|
Points |
Two |
None |
One |
|
Chip risk |
Protect both tips |
Lowest |
Protect one tip |
|
Bow-tie |
Check each stone |
Check each stone |
Check each stone |
|
Finger effect |
Strongest lengthening |
Soft lengthening |
Directional lengthening |
-
Choose a marquise for maximum length and a bold silhouette.
-
Choose an oval diamond for a softer outline with no points.
-
Choose a pear diamond for a single point and a teardrop shape.
-
Stay with a round brilliant if sparkle matters most, as it returns the most light but looks smallest per carat.
Get the Right Marquise Diamond Jewellery Today!
Ready to see them? Explore a certified marquise diamond ring in lab-grown or natural, or book a virtual appointment with a diamond expert today.
Marquise Diamond FAQs
Does a marquise diamond look bigger?
Yes. A marquise diamond typically faces up around 10% to 15% larger than a round brilliant of the same carat weight, because its elongated shape spreads weight across the surface.
What is the best length-to-width ratio for a marquise diamond?
Most jewellers treat 1.75 to 2.25 as the workable range, and a ratio near 2.0 gives the classic look. Lower ratios look fuller, while higher ratios look slimmer.
Are the points on a marquise diamond fragile?
The points are the most chip-prone part of a marquise cut diamond, but V-prongs or a bezel protect them well. With the right setting, a marquise ring suits everyday wear.
What is the bow-tie effect in a marquise diamond?
The bow-tie is a darker band across the centre of the stone, where light escapes instead of returning to your eye. Most elongated brilliants show some, and excellent symmetry keeps it subtle.
Are lab-grown marquise diamonds real diamonds?
Yes. Lab-grown marquise diamonds have the same chemistry, hardness and sparkle as mined stones. Rings of Australia supplies them with GIA or IGI certificates.
How much does a marquise diamond ring cost in Australia?
The price depends on carat, ratio, colour, clarity, origin and setting. A lab-grown marquise diamond ring costs less than a natural one of the same size and grade, and our live collection pages show current prices.
Is a marquise a good shape for an engagement ring?
Yes, if you want a long, distinctive stone with strong finger coverage. Choose a setting that covers both tips, and the marquise diamond ring will wear well day to day.
