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28ct Amethyst (Cabochon, 23.84×15.89mm, Violet) vs 28ct Alexandrite (Cabochon, 21.27×14.18mm, Bluish Green)


Quick summary: When looked from above (face-up position), 28ct Amethyst (23.84×15.89mm, cabochon cut) appears 26% larger than 28ct Alexandrite (21.27×14.18mm, cabochon cut). See below how they compare side-by-side on a ring and finger.

28ct Amethyst (cabochon cut)
vs
 28ct Alexandrite (cabochon cut)
violet
 
bluish green
23.84×15.89 mm 21.27×14.18 mm
actual size
Actual size of 28ct Amethyst (cabochon cut, 23.84×15.89mm, Violet color)   Actual size of 28ct Alexandrite (cabochon cut, 21.27×14.18mm, 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 28ct Amethyst (cabochon cut, 23.84×15.89mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Bluish Green 28ct Alexandrite (cabochon cut, 21.27×14.18mm) 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
 95% vs 84%
Saved...
Ring diameter: 16.9 mm
USA UK Asia EU1 EU2
Actual sizes of 28ct Amethyst Cabochon (23.84×15.89mm, Violet) and 28ct Alexandrite Cabochon (21.27×14.18mm, 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.


28 Ct Amethyst (Cabochon) 28 Ct Alexandrite (Cabochon)
23.84×15.89 mm vs 21.27×14.18 mm
310.63 mm²   247.32 mm²
Face-up size outline for 28ct Amethyst (23.84×15.89mm, cabochon cut)
Face-up size outline for 28ct Alexandrite (21.27×14.18mm, cabochon cut)
28ct Amethyst Cabochon (23.84×15.89mm)
28ct Alexandrite Cabochon (21.27×14.18mm)
Difference: 26% (63.31 mm²)
28ct Amethyst (Cabochon, 23.84×15.89mm) has approx. 26% more face-up area than 28ct Alexandrite (Cabochon, 21.27×14.18mm).


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