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1ct Diamond (Round, 6.5×6.5mm, Blue) vs 1ct Ruby (Round, 5.98×5.98mm, Red)


Quick summary: When looked from above (face-up position), 1ct Colored Diamond (6.5×6.5mm, round cut) appears 18% larger than 1ct Ruby (5.98×5.98mm, round cut). See below how they compare side-by-side on a ring and finger.

1ct Diamond (round cut)
vs
 1ct Ruby (round cut)
blue
 
red
6.5×6.5 mm 5.98×5.98 mm
actual size
Actual size of 1ct Diamond (round cut, 6.5×6.5mm, Blue color)   Actual size of 1ct Ruby (round cut, 5.98×5.98mm, Red color)
 
Actual size is set for screen
Ring: Skin tone:
Ring width: 3.0 mm
Left finger image
Ring on left finger
Blue 1ct Diamond (round cut, 6.5×6.5mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Red 1ct Ruby (round cut, 5.98×5.98mm) 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
 39% vs 36%
Saved...
Ring diameter: 16.9 mm
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Actual sizes of 1ct Diamond Round (6.5×6.5mm, Blue) and 1ct Ruby Round (5.98×5.98mm, Red) 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, Ruby 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.


1 Ct Colored Diamond (Round) 1 Ct Ruby (Round)
6.5×6.5 mm vs 5.98×5.98 mm
33.18 mm²   28.09 mm²
Face-up size outline for 1ct Diamond (6.5×6.5mm, round cut)
Face-up size outline for 1ct Ruby (5.98×5.98mm, round cut)
1ct Colored Diamond Round (6.5×6.5mm)
1ct Ruby Round (5.98×5.98mm)
Difference: 18% (5.09 mm²)
1ct Colored Diamond (Round, 6.5×6.5mm) has approx. 18% more face-up area than 1ct Ruby (Round, 5.98×5.98mm).


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