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36ct Alexandrite (Round, 20.21×20.21mm, Bluish Green) vs 36ct Topaz (Round, 20.58×20.58mm, Blue)


Quick summary: When looked from above (face-up position), 36ct Topaz (20.58×20.58mm, round cut) appears 4% larger than 36ct Alexandrite (20.21×20.21mm, round cut). See below how they compare side-by-side on a ring and finger.

36ct Alexandrite (round cut)
vs
 36ct Topaz (round cut)
bluish green
 
blue
20.21×20.21 mm 20.58×20.58 mm
actual size
Actual size of 36ct Alexandrite (round cut, 20.21×20.21mm, Bluish Green color)   Actual size of 36ct Topaz (round cut, 20.58×20.58mm, 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 36ct Alexandrite (round cut, 20.21×20.21mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Blue 36ct Topaz (round cut, 20.58×20.58mm) 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
 120% vs 122%
Saved...
Ring diameter: 16.9 mm
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Actual sizes of 36ct Alexandrite Round (20.21×20.21mm, Bluish Green) and 36ct Topaz Round (20.58×20.58mm, 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.


36 Ct Alexandrite (Round) 36 Ct Topaz (Round)
20.21×20.21 mm vs 20.58×20.58 mm
320.79 mm²   332.64 mm²
Face-up size outline for 36ct Topaz (20.58×20.58mm, round cut)
Face-up size outline for 36ct Alexandrite (20.21×20.21mm, round cut)
36ct Alexandrite Round (20.21×20.21mm)
36ct Topaz Round (20.58×20.58mm)
Difference: 4% (11.85 mm²)
36ct Topaz (Round, 20.58×20.58mm) has approx. 4% more face-up area than 36ct Alexandrite (Round, 20.21×20.21mm).


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