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16ct Amethyst (Cabochon, 19.79×13.19mm, Violet) vs 16ct Alexandrite (Cabochon, 17.66×11.77mm, Bluish Green)


Quick summary: When looked from above (face-up position), 16ct Amethyst (19.79×13.19mm, cabochon cut) appears 26% larger than 16ct Alexandrite (17.66×11.77mm, cabochon cut). See below how they compare side-by-side on a ring and finger.

16ct Amethyst (cabochon cut)
vs
 16ct Alexandrite (cabochon cut)
violet
 
bluish green
19.79×13.19 mm 17.66×11.77 mm
actual size
Actual size of 16ct Amethyst (cabochon cut, 19.79×13.19mm, Violet color)   Actual size of 16ct Alexandrite (cabochon cut, 17.66×11.77mm, 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 16ct Amethyst (cabochon cut, 19.79×13.19mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Bluish Green 16ct Alexandrite (cabochon cut, 17.66×11.77mm) 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
 79% vs 70%
Saved...
Ring diameter: 16.9 mm
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Actual sizes of 16ct Amethyst Cabochon (19.79×13.19mm, Violet) and 16ct Alexandrite Cabochon (17.66×11.77mm, 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.


16 Ct Amethyst (Cabochon) 16 Ct Alexandrite (Cabochon)
19.79×13.19 mm vs 17.66×11.77 mm
214.04 mm²   170.44 mm²
Face-up size outline for 16ct Amethyst (19.79×13.19mm, cabochon cut)
Face-up size outline for 16ct Alexandrite (17.66×11.77mm, cabochon cut)
16ct Amethyst Cabochon (19.79×13.19mm)
16ct Alexandrite Cabochon (17.66×11.77mm)
Difference: 26% (43.6 mm²)
16ct Amethyst (Cabochon, 19.79×13.19mm) has approx. 26% more face-up area than 16ct Alexandrite (Cabochon, 17.66×11.77mm).


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