×
carat vs. color  length*  width*
  ×

(or examine a )
* size in mm (optional)

17ct Amethyst (Trillion, 21.56×21.56mm, Violet) vs 17ct Alexandrite (Trillion, 19.24×19.24mm, Bluish Green)


Quick summary: When looked from above (face-up position), 17ct Amethyst (21.56×21.56mm, trillion cut) appears 26% larger than 17ct Alexandrite (19.24×19.24mm, trillion cut). See below how they compare side-by-side on a ring and finger.

17ct Amethyst (trillion cut)
vs
17ct Alexandrite (trillion cut)
violet
 
bluish green
21.56×21.56 mm 19.24×19.24 mm
actual size
Actual size of 17ct Amethyst (trillion cut, 21.56×21.56mm, Violet color)   Actual size of 17ct Alexandrite (trillion cut, 19.24×19.24mm, 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 17ct Amethyst (trillion cut, 21.56×21.56mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Bluish Green 17ct Alexandrite (trillion cut, 19.24×19.24mm) 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
128% vs 114%
Saved...
Ring diameter: 16.9 mm
USA UK Asia EU1 EU2
Actual sizes of 17ct Amethyst Trillion (21.56×21.56mm, Violet) and 17ct Alexandrite Trillion (19.24×19.24mm, 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.


17 Ct Amethyst (Trillion) 17 Ct Alexandrite (Trillion)
21.56×21.56 mm vs 19.24×19.24 mm
288.2 mm²   229.51 mm²
Face-up size outline for 17ct Amethyst (21.56×21.56mm, trillion cut)
Face-up size outline for 17ct Alexandrite (19.24×19.24mm, trillion cut)
17ct Amethyst Trillion (21.56×21.56mm)
17ct Alexandrite Trillion (19.24×19.24mm)
Difference: 26% (58.69 mm²)
17ct Amethyst (Trillion, 21.56×21.56mm) has approx. 26% more face-up area than 17ct Alexandrite (Trillion, 19.24×19.24mm).


Popular comparisons: