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13ct Benitoite (Oval, 18.59×12.39mm, Blue) vs 13ct Alexandrite (Oval, 18.45×12.3mm, Bluish Green)


Quick summary: When looked from above (face-up position), 13ct Benitoite (18.59×12.39mm, oval cut) appears 1% larger than 13ct Alexandrite (18.45×12.3mm, oval cut). See below how they compare side-by-side on a ring and finger.

13ct Benitoite (oval cut)
vs
 13ct Alexandrite (oval cut)
blue
 
bluish green
18.59×12.39 mm 18.45×12.3 mm
actual size
Actual size of 13ct Benitoite (oval cut, 18.59×12.39mm, Blue color)   Actual size of 13ct Alexandrite (oval cut, 18.45×12.3mm, 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 13ct Benitoite (oval cut, 18.59×12.39mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Bluish Green 13ct Alexandrite (oval cut, 18.45×12.3mm) 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
 74% vs 73%
Saved...
Ring diameter: 16.9 mm
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Actual sizes of 13ct Benitoite Oval (18.59×12.39mm, Blue) and 13ct Alexandrite Oval (18.45×12.3mm, 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.


13 Ct Benitoite (Oval) 13 Ct Alexandrite (Oval)
18.59×12.39 mm vs 18.45×12.3 mm
188.87 mm²   186.09 mm²
Face-up size outline for 13ct Benitoite (18.59×12.39mm, oval cut)
Face-up size outline for 13ct Alexandrite (18.45×12.3mm, oval cut)
13ct Benitoite Oval (18.59×12.39mm)
13ct Alexandrite Oval (18.45×12.3mm)
Difference: 1% (2.78 mm²)
13ct Benitoite (Oval, 18.59×12.39mm) has approx. 1% more face-up area than 13ct Alexandrite (Oval, 18.45×12.3mm).


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