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3ct Diamond (Round, 9.37×9.37mm, Black) vs 3ct Tourmaline (Round, 9.39×9.39mm, Yellow)


Quick summary: When looked from above (face-up position), 3ct Tourmaline (9.39×9.39mm, round cut) appears 0.4% larger than 3ct Colored Diamond (9.37×9.37mm, round cut). See below how they compare side-by-side on a ring and finger.

3ct Diamond (round cut)
vs
 3ct Tourmaline (round cut)
black
 
yellow
9.37×9.37 mm 9.39×9.39 mm
actual size
Actual size of 3ct Diamond (round cut, 9.37×9.37mm, Black color)   Actual size of 3ct Tourmaline (round cut, 9.39×9.39mm, Yellow color)
 
Actual size is set for screen
Ring: Skin tone:
Ring width: 3.0 mm
Left finger image
Ring on left finger
Black 3ct Diamond (round cut, 9.37×9.37mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Yellow 3ct Tourmaline (round cut, 9.39×9.39mm) 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
 56% vs 56%
Saved...
Ring diameter: 16.9 mm
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Actual sizes of 3ct Diamond Round (9.37×9.37mm, Black) and 3ct Tourmaline Round (9.39×9.39mm, Yellow) 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

All things being equal, Diamond will face-up smaller than Tourmaline for a given carat weight, because it has higher specific gravity (3.52 vs. 3.06 - this means it's "heavier" compared to Tourmaline of the same size). Face-up size also depends heavily on 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.


3 Ct Colored Diamond (Round) 3 Ct Tourmaline (Round)
9.37×9.37 mm vs 9.39×9.39 mm
68.96 mm²   69.25 mm²
Face-up size outline for 3ct Tourmaline (9.39×9.39mm, round cut)
Face-up size outline for 3ct Diamond (9.37×9.37mm, round cut)
3ct Colored Diamond Round (9.37×9.37mm)
3ct Tourmaline Round (9.39×9.39mm)
Difference: 0.4% (0.29 mm²)
3ct Tourmaline (Round, 9.39×9.39mm) has approx. 0.4% more face-up area than 3ct Colored Diamond (Round, 9.37×9.37mm).


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