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13ct Alexandrite (Asscher, 12.83×12.83mm, Bluish Green) vs 13ct Topaz (Asscher, 13.07×13.07mm, Blue)


Quick summary: When looked from above (face-up position), 13ct Topaz (13.07×13.07mm, asscher cut) appears 4% larger than 13ct Alexandrite (12.83×12.83mm, asscher cut). See below how they compare side-by-side on a ring and finger.

13ct Alexandrite (asscher cut)
vs
 13ct Topaz (asscher cut)
bluish green
 
blue
12.83×12.83 mm 13.07×13.07 mm
actual size
Actual size of 13ct Alexandrite (asscher cut, 12.83×12.83mm, Bluish Green color)   Actual size of 13ct Topaz (asscher cut, 13.07×13.07mm, 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 13ct Alexandrite (asscher cut, 12.83×12.83mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Blue 13ct Topaz (asscher cut, 13.07×13.07mm) 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
 76% vs 78%
Saved...
Ring diameter: 16.9 mm
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Actual sizes of 13ct Alexandrite Asscher (12.83×12.83mm, Bluish Green) and 13ct Topaz Asscher (13.07×13.07mm, 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.


13 Ct Alexandrite (Asscher) 13 Ct Topaz (Asscher)
12.83×12.83 mm vs 13.07×13.07 mm
151.44 mm²   157.16 mm²
Face-up size outline for 13ct Topaz (13.07×13.07mm, asscher cut)
Face-up size outline for 13ct Alexandrite (12.83×12.83mm, asscher cut)
13ct Alexandrite Asscher (12.83×12.83mm)
13ct Topaz Asscher (13.07×13.07mm)
Difference: 4% (5.72 mm²)
13ct Topaz (Asscher, 13.07×13.07mm) has approx. 4% more face-up area than 13ct Alexandrite (Asscher, 12.83×12.83mm).


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