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18ct Diamond (Oval, 21.27×14.18mm, White) vs 1ct Diamond (Marquise, 10.38×5.19mm, White)


Quick summary: When looked from above (face-up position), 18ct Diamond (21.27×14.18mm, oval cut) appears 6.5 times larger than 1ct Diamond (10.38×5.19mm, marquise cut). See below how they compare side-by-side on a ring and finger.

18ct Diamond (oval cut)
vs
 1ct Diamond (marquise cut)
white
 
white
21.27×14.18 mm 10.38×5.19 mm
actual size
Actual size of 18ct Diamond (oval cut, 21.27×14.18mm, White color)   Actual size of 1ct Diamond (marquise cut, 10.38×5.19mm, White color)
 
Actual size is set for screen
Ring: Skin tone:
Ring width: 3.0 mm
Left finger image
Ring on left finger
White 18ct Diamond (oval cut, 21.27×14.18mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
White 1ct Diamond (marquise cut, 10.38×5.19mm) on a right ring and finger
Your settings
Ring
 Gold
Skin tone
 Light
Ring diameter
 16.9 mm
Ring width
 3.0 mm
Finger length
 64 mm
Finger coverage
 84% vs 31%
Saved...
Ring diameter: 16.9 mm
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Actual sizes of 18ct Diamond Oval (21.27×14.18mm, White) and 1ct Diamond Marquise (10.38×5.19mm, White) as they would appear on a ring and finger. Adjust the ring and finger size to get an idea of how these gemstones would look on your finger.

Where to buy?

For certified gemstones, high-end gemstone jewelry, and birthstone jewelry, see Blue Nile

Face-up Size

The face-up size depends on the shape of the gem, its weight and the proportions of the cut. Face-up area is a measure of the size of the gem when viewed from above (as set in a ring). It tells you how big the gem is at the girdle plane.


18 Ct Diamond (Oval) 1 Ct Diamond (Marquise)
21.27×14.18 mm vs 10.38×5.19 mm
247.32 mm²   38.25 mm²
Face-up size outline for 18ct Diamond (21.27×14.18mm, oval cut)
Face-up size outline for 1ct Diamond (10.38×5.19mm, marquise cut)
18ct Diamond Oval (21.27×14.18mm)
1ct Diamond Marquise (10.38×5.19mm)
Difference: 547% (209.07 mm²)
18ct Diamond (Oval, 21.27×14.18mm) has approx. 547% more face-up area than 1ct Diamond (Marquise, 10.38×5.19mm). In other words, it's 6.47x larger.


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