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2.5ct Ruby (Round, 8.11×8.11mm, Red) vs 1.5ct Alexandrite (Round, 7.02×7.02mm, Bluish Green)


Quick summary: When looked from above (face-up position), 2.5ct Ruby (8.11×8.11mm, round cut) appears 33% larger than 1.5ct Alexandrite (7.02×7.02mm, round cut). See below how they compare side-by-side on a ring and finger.

2.5ct Ruby (round cut)
vs
 1.5ct Alexandrite (round cut)
red
 
bluish green
8.11×8.11 mm 7.02×7.02 mm
actual size
Actual size of 2.5ct Ruby (round cut, 8.11×8.11mm, Red color)   Actual size of 1.5ct Alexandrite (round cut, 7.02×7.02mm, Bluish Green color)
 
Actual size is set for screen
Ring: Skin tone:
Ring width: 3.0 mm
Left finger image
Ring on left finger
Red 2.5ct Ruby (round cut, 8.11×8.11mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Bluish Green 1.5ct Alexandrite (round cut, 7.02×7.02mm) 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
 48% vs 42%
Saved...
Ring diameter: 16.9 mm
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Actual sizes of 2.5ct Ruby Round (8.11×8.11mm, Red) and 1.5ct Alexandrite Round (7.02×7.02mm, Bluish Green) 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 Alexandrite for a given carat weight, because it has higher specific gravity (4 vs. 3.73 - this means it's "heavier" compared to Alexandrite 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.


2.5 Ct Ruby (Round) 1.5 Ct Alexandrite (Round)
8.11×8.11 mm vs 7.02×7.02 mm
51.66 mm²   38.7 mm²
Face-up size outline for 2.5ct Ruby (8.11×8.11mm, round cut)
Face-up size outline for 1.5ct Alexandrite (7.02×7.02mm, round cut)
2.5ct Ruby Round (8.11×8.11mm)
1.5ct Alexandrite Round (7.02×7.02mm)
Difference: 33% (12.96 mm²)
2.5ct Ruby (Round, 8.11×8.11mm) has approx. 33% more face-up area than 1.5ct Alexandrite (Round, 7.02×7.02mm).


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