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40ct Benitoite (Round, 21.08×21.08mm, Blue) vs 40ct Alexandrite (Round, 20.93×20.93mm, Bluish Green)


Quick summary: When looked from above (face-up position), 40ct Benitoite (21.08×21.08mm, round cut) appears 1% larger than 40ct Alexandrite (20.93×20.93mm, round cut). See below how they compare side-by-side on a ring and finger.

40ct Benitoite (round cut)
vs
 40ct Alexandrite (round cut)
blue
 
bluish green
21.08×21.08 mm 20.93×20.93 mm
actual size
Actual size of 40ct Benitoite (round cut, 21.08×21.08mm, Blue color)   Actual size of 40ct Alexandrite (round cut, 20.93×20.93mm, Bluish Green color)
Actual size is set for screen
Ring: Skin tone:
Ring width: 3.0 mm
Left finger image
Ring on left finger
Blue 40ct Benitoite (round cut, 21.08×21.08mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Bluish Green 40ct Alexandrite (round cut, 20.93×20.93mm) 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
 125% vs 124%
Saved...
Ring diameter: 16.9 mm
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Actual sizes of 40ct Benitoite Round (21.08×21.08mm, Blue) and 40ct Alexandrite Round (20.93×20.93mm, 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, Alexandrite will face-up slightly smaller than Benitoite for a given carat weight, because it has higher specific gravity (3.73 vs. 3.65 - this means it's "slightly heavier" compared to Benitoite 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 Benitoite (Round) 40 Ct Alexandrite (Round)
21.08×21.08 mm vs 20.93×20.93 mm
349 mm²   344.06 mm²
Face-up size outline for 40ct Benitoite (21.08×21.08mm, round cut)
Face-up size outline for 40ct Alexandrite (20.93×20.93mm, round cut)
40ct Benitoite Round (21.08×21.08mm)
40ct Alexandrite Round (20.93×20.93mm)
Difference: 1% (4.94 mm²)
40ct Benitoite (Round, 21.08×21.08mm) has approx. 1% more face-up area than 40ct Alexandrite (Round, 20.93×20.93mm).


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