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40ct Amethyst (Princess, 20.61×20.61mm, Violet) vs 40ct Alexandrite (Princess, 18.39×18.39mm, Bluish Green)


Quick summary: When looked from above (face-up position), 40ct Amethyst (20.61×20.61mm, princess cut) appears 26% larger than 40ct Alexandrite (18.39×18.39mm, princess cut). See below how they compare side-by-side on a ring and finger.

40ct Amethyst (princess cut)
vs
 40ct Alexandrite (princess cut)
violet
 
bluish green
20.61×20.61 mm 18.39×18.39 mm
actual size
Actual size of 40ct Amethyst (princess cut, 20.61×20.61mm, Violet color)   Actual size of 40ct Alexandrite (princess cut, 18.39×18.39mm, Bluish Green color)
 
Actual size is set for screen
Ring: Skin tone:
Ring width: 3.0 mm
Left finger image
Ring on left finger
Violet 40ct Amethyst (princess cut, 20.61×20.61mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Bluish Green 40ct Alexandrite (princess cut, 18.39×18.39mm) 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
 122% vs 109%
Saved...
Ring diameter: 16.9 mm
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Actual sizes of 40ct Amethyst Princess (20.61×20.61mm, Violet) and 40ct Alexandrite Princess (18.39×18.39mm, 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 smaller than Amethyst for a given carat weight, because it has higher specific gravity (3.73 vs. 2.65 - this means it's "heavier" compared to Amethyst 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 Amethyst (Princess) 40 Ct Alexandrite (Princess)
20.61×20.61 mm vs 18.39×18.39 mm
424.77 mm²   338.19 mm²
Face-up size outline for 40ct Amethyst (20.61×20.61mm, princess cut)
Face-up size outline for 40ct Alexandrite (18.39×18.39mm, princess cut)
40ct Amethyst Princess (20.61×20.61mm)
40ct Alexandrite Princess (18.39×18.39mm)
Difference: 26% (86.58 mm²)
40ct Amethyst (Princess, 20.61×20.61mm) has approx. 26% more face-up area than 40ct Alexandrite (Princess, 18.39×18.39mm).


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