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40ct Ruby (Emerald, 21.84×16.18mm, Red) vs 10ct Alexandrite (Cushion, 12.36×12.36mm, Bluish Green)


Quick summary: When looked from above (face-up position), 40ct Ruby (21.84×16.18mm, emerald cut) appears 2.4 times larger than 10ct Alexandrite (12.36×12.36mm, cushion cut). See below how they compare side-by-side on a ring and finger.

40ct Ruby (emerald cut)
vs
 10ct Alexandrite (cushion cut)
red
 
bluish green
21.84×16.18 mm 12.36×12.36 mm
actual size
Actual size of 40ct Ruby (emerald cut, 21.84×16.18mm, Red color)   Actual size of 10ct Alexandrite (cushion cut, 12.36×12.36mm, 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 40ct Ruby (emerald cut, 21.84×16.18mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Bluish Green 10ct Alexandrite (cushion cut, 12.36×12.36mm) 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
 96% vs 74%
Saved...
Ring diameter: 16.9 mm
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Actual sizes of 40ct Ruby Emerald (21.84×16.18mm, Red) and 10ct Alexandrite Cushion (12.36×12.36mm, 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.


40 Ct Ruby (Emerald) 10 Ct Alexandrite (Cushion)
21.84×16.18 mm vs 12.36×12.36 mm
328.64 mm²   137.49 mm²
Face-up size outline for 40ct Ruby (21.84×16.18mm, emerald cut)
Face-up size outline for 10ct Alexandrite (12.36×12.36mm, cushion cut)
40ct Ruby Emerald (21.84×16.18mm)
10ct Alexandrite Cushion (12.36×12.36mm)
Difference: 139% (191.15 mm²)
40ct Ruby (Emerald, 21.84×16.18mm) has approx. 139% more face-up area than 10ct Alexandrite (Cushion, 12.36×12.36mm). In other words, it's 2.39x larger.


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