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40ct Benitoite (Asscher, 18.8×18.8mm, Blue) vs 40ct Alexandrite (Asscher, 18.66×18.66mm, Bluish Green)


Quick summary: When looked from above (face-up position), 40ct Benitoite (18.8×18.8mm, asscher cut) appears 2% larger than 40ct Alexandrite (18.66×18.66mm, asscher cut). See below how they compare side-by-side on a ring and finger.

40ct Benitoite (asscher cut)
vs
 40ct Alexandrite (asscher cut)
blue
 
bluish green
18.8×18.8 mm 18.66×18.66 mm
actual size
Actual size of 40ct Benitoite (asscher cut, 18.8×18.8mm, Blue color)   Actual size of 40ct Alexandrite (asscher cut, 18.66×18.66mm, 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 (asscher cut, 18.8×18.8mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Bluish Green 40ct Alexandrite (asscher cut, 18.66×18.66mm) 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
 112% vs 111%
Saved...
Ring diameter: 16.9 mm
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Actual sizes of 40ct Benitoite Asscher (18.8×18.8mm, Blue) and 40ct Alexandrite Asscher (18.66×18.66mm, 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 (Asscher) 40 Ct Alexandrite (Asscher)
18.8×18.8 mm vs 18.66×18.66 mm
325.16 mm²   320.34 mm²
Face-up size outline for 40ct Benitoite (18.8×18.8mm, asscher cut)
Face-up size outline for 40ct Alexandrite (18.66×18.66mm, asscher cut)
40ct Benitoite Asscher (18.8×18.8mm)
40ct Alexandrite Asscher (18.66×18.66mm)
Difference: 2% (4.82 mm²)
40ct Benitoite (Asscher, 18.8×18.8mm) has approx. 2% more face-up area than 40ct Alexandrite (Asscher, 18.66×18.66mm).


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