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5ct Sapphire (Trillion, 12.02×12.02mm, Blue) vs 3.5ct Diamond (Round, 9.87×9.87mm, White)


Quick summary: When looked from above (face-up position), 5ct Sapphire (12.02×12.02mm, trillion cut) appears 17% larger than 3.5ct Diamond (9.87×9.87mm, round cut). See below how they compare side-by-side on a ring and finger.

5ct Sapphire (trillion cut)
vs
 3.5ct Diamond (round cut)
blue
 
white
12.02×12.02 mm 9.87×9.87 mm
actual size
Actual size of 5ct Sapphire (trillion cut, 12.02×12.02mm, Blue color)   Actual size of 3.5ct Diamond (round cut, 9.87×9.87mm, White color)
 
Actual size is set for screen
Ring: Skin tone:
Ring width: 3.0 mm
Left finger image
Ring on left finger
Blue 5ct Sapphire (trillion cut, 12.02×12.02mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
White 3.5ct Diamond (round cut, 9.87×9.87mm) 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
 72% vs 59%
Saved...
Ring diameter: 16.9 mm
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Actual sizes of 5ct Sapphire Trillion (12.02×12.02mm, Blue) and 3.5ct Diamond Round (9.87×9.87mm, 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

All things being equal, Sapphire will face-up smaller than Diamond for a given carat weight, because it has higher specific gravity (4 vs. 3.52 - this means it's "heavier" compared to Diamond 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.


5 Ct Sapphire (Trillion) 3.5 Ct Diamond (Round)
12.02×12.02 mm vs 9.87×9.87 mm
89.58 mm²   76.51 mm²
Face-up size outline for 5ct Sapphire (12.02×12.02mm, trillion cut)
Face-up size outline for 3.5ct Diamond (9.87×9.87mm, round cut)
5ct Sapphire Trillion (12.02×12.02mm)
3.5ct Diamond Round (9.87×9.87mm)
Difference: 17% (13.07 mm²)
5ct Sapphire (Trillion, 12.02×12.02mm) has approx. 17% more face-up area than 3.5ct Diamond (Round, 9.87×9.87mm).


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