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13ct Alexandrite (Pear, 20.47×12.33mm, Bluish Green) vs 13ct Topaz (Pear, 20.85×12.56mm, Blue)


Quick summary: When looked from above (face-up position), 13ct Topaz (20.85×12.56mm, pear cut) appears 4% larger than 13ct Alexandrite (20.47×12.33mm, pear cut). See below how they compare side-by-side on a ring and finger.

13ct Alexandrite (pear cut)
vs
 13ct Topaz (pear cut)
bluish green
 
blue
20.47×12.33 mm 20.85×12.56 mm
actual size
Actual size of 13ct Alexandrite (pear cut, 20.47×12.33mm, Bluish Green color)   Actual size of 13ct Topaz (pear cut, 20.85×12.56mm, 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 (pear cut, 20.47×12.33mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Blue 13ct Topaz (pear cut, 20.85×12.56mm) 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
 73% vs 75%
Saved...
Ring diameter: 16.9 mm
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Actual sizes of 13ct Alexandrite Pear (20.47×12.33mm, Bluish Green) and 13ct Topaz Pear (20.85×12.56mm, 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 (Pear) 13 Ct Topaz (Pear)
20.47×12.33 mm vs 20.85×12.56 mm
184.25 mm²   191.17 mm²
Face-up size outline for 13ct Topaz (20.85×12.56mm, pear cut)
Face-up size outline for 13ct Alexandrite (20.47×12.33mm, pear cut)
13ct Alexandrite Pear (20.47×12.33mm)
13ct Topaz Pear (20.85×12.56mm)
Difference: 4% (6.92 mm²)
13ct Topaz (Pear, 20.85×12.56mm) has approx. 4% more face-up area than 13ct Alexandrite (Pear, 20.47×12.33mm).


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