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40ct Amethyst (Trillion, 28.68×28.68mm, Violet) vs 40ct Alexandrite (Trillion, 25.59×25.59mm, Bluish Green)


Quick summary: When looked from above (face-up position), 40ct Amethyst (28.68×28.68mm, trillion cut) appears 26% larger than 40ct Alexandrite (25.59×25.59mm, trillion cut). See below how they compare side-by-side on a ring and finger.

40ct Amethyst (trillion cut)
vs
40ct Alexandrite (trillion cut)
violet
 
bluish green
28.68×28.68 mm 25.59×25.59 mm
actual size
Actual size of 40ct Amethyst (trillion cut, 28.68×28.68mm, Violet color)   Actual size of 40ct Alexandrite (trillion cut, 25.59×25.59mm, 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 (trillion cut, 28.68×28.68mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Bluish Green 40ct Alexandrite (trillion cut, 25.59×25.59mm) 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
170% vs 152%
Saved...
Ring diameter: 16.9 mm
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Actual sizes of 40ct Amethyst Trillion (28.68×28.68mm, Violet) and 40ct Alexandrite Trillion (25.59×25.59mm, 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 (Trillion) 40 Ct Alexandrite (Trillion)
28.68×28.68 mm vs 25.59×25.59 mm
509.98 mm²   406.01 mm²
Face-up size outline for 40ct Amethyst (28.68×28.68mm, trillion cut)
Face-up size outline for 40ct Alexandrite (25.59×25.59mm, trillion cut)
40ct Amethyst Trillion (28.68×28.68mm)
40ct Alexandrite Trillion (25.59×25.59mm)
Difference: 26% (103.97 mm²)
40ct Amethyst (Trillion, 28.68×28.68mm) has approx. 26% more face-up area than 40ct Alexandrite (Trillion, 25.59×25.59mm).


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