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20ct Alexandrite (Asscher, 14.81×14.81mm, Bluish Green) vs 20ct Topaz (Asscher, 15.09×15.09mm, Blue)


Quick summary: When looked from above (face-up position), 20ct Topaz (15.09×15.09mm, asscher cut) appears 4% larger than 20ct Alexandrite (14.81×14.81mm, asscher cut). See below how they compare side-by-side on a ring and finger.

20ct Alexandrite (asscher cut)
vs
20ct Topaz (asscher cut)
bluish green
 
blue
14.81×14.81 mm 15.09×15.09 mm
actual size
Actual size of 20ct Alexandrite (asscher cut, 14.81×14.81mm, Bluish Green color)   Actual size of 20ct Topaz (asscher cut, 15.09×15.09mm, Blue color)
 
Actual size is set for screen
Ring: Skin tone:
Ring width: 3.0 mm
Left finger image
Ring on left finger
Bluish Green 20ct Alexandrite (asscher cut, 14.81×14.81mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Blue 20ct Topaz (asscher cut, 15.09×15.09mm) 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
88% vs 90%
Saved...
Ring diameter: 16.9 mm
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Actual sizes of 20ct Alexandrite Asscher (14.81×14.81mm, Bluish Green) and 20ct Topaz Asscher (15.09×15.09mm, Blue) 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 Topaz for a given carat weight, because it has higher specific gravity (3.73 vs. 3.53 - this means it's "heavier" compared to Topaz 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 Alexandrite (Asscher) 20 Ct Topaz (Asscher)
14.81×14.81 mm vs 15.09×15.09 mm
201.79 mm²   209.49 mm²
Face-up size outline for 20ct Topaz (15.09×15.09mm, asscher cut)
Face-up size outline for 20ct Alexandrite (14.81×14.81mm, asscher cut)
20ct Alexandrite Asscher (14.81×14.81mm)
20ct Topaz Asscher (15.09×15.09mm)
Difference: 4% (7.7 mm²)
20ct Topaz (Asscher, 15.09×15.09mm) has approx. 4% more face-up area than 20ct Alexandrite (Asscher, 14.81×14.81mm).


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