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20ct Amethyst (Cushion, 17.24×17.24mm, Violet) vs 20ct Alexandrite (Cushion, 15.38×15.38mm, Bluish Green)


Quick summary: When looked from above (face-up position), 20ct Amethyst (17.24×17.24mm, cushion cut) appears 26% larger than 20ct Alexandrite (15.38×15.38mm, cushion cut). See below how they compare side-by-side on a ring and finger.

20ct Amethyst (cushion cut)
vs
 20ct Alexandrite (cushion cut)
violet
 
bluish green
17.24×17.24 mm 15.38×15.38 mm
actual size
Actual size of 20ct Amethyst (cushion cut, 17.24×17.24mm, Violet color)   Actual size of 20ct Alexandrite (cushion cut, 15.38×15.38mm, 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 20ct Amethyst (cushion cut, 17.24×17.24mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Bluish Green 20ct Alexandrite (cushion cut, 15.38×15.38mm) 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
 103% vs 92%
Saved...
Ring diameter: 16.9 mm
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Actual sizes of 20ct Amethyst Cushion (17.24×17.24mm, Violet) and 20ct Alexandrite Cushion (15.38×15.38mm, 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.


20 Ct Amethyst (Cushion) 20 Ct Alexandrite (Cushion)
17.24×17.24 mm vs 15.38×15.38 mm
267.5 mm²   212.89 mm²
Face-up size outline for 20ct Amethyst (17.24×17.24mm, cushion cut)
Face-up size outline for 20ct Alexandrite (15.38×15.38mm, cushion cut)
20ct Amethyst Cushion (17.24×17.24mm)
20ct Alexandrite Cushion (15.38×15.38mm)
Difference: 26% (54.61 mm²)
20ct Amethyst (Cushion, 17.24×17.24mm) has approx. 26% more face-up area than 20ct Alexandrite (Cushion, 15.38×15.38mm).


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