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0.25ct Alexandrite (Round, 3.85×3.85mm, Bluish Green) vs 0.25ct Diamond (Round, 4.09×4.09mm, White)


Quick summary: When looked from above (face-up position), 0.25ct Diamond (4.09×4.09mm, round cut) appears 13% larger than 0.25ct Alexandrite (3.85×3.85mm, round cut). See below how they compare side-by-side on a ring and finger.

0.25ct Alexandrite (round cut)
vs
 0.25ct Diamond (round cut)
bluish green
 
white
3.85×3.85 mm 4.09×4.09 mm
actual size
Actual size of 0.25ct Alexandrite (round cut, 3.85×3.85mm, Bluish Green color)   Actual size of 0.25ct Diamond (round cut, 4.09×4.09mm, White color)
 
Actual size is set for screen
Ring: Skin tone:
Ring width: 3.0 mm
Left finger image
Ring on left finger
Bluish Green 0.25ct Alexandrite (round cut, 3.85×3.85mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
White 0.25ct Diamond (round cut, 4.09×4.09mm) 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
 23% vs 25%
Saved...
Ring diameter: 16.9 mm
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Actual sizes of 0.25ct Alexandrite Round (3.85×3.85mm, Bluish Green) and 0.25ct Diamond Round (4.09×4.09mm, White) 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 Diamond for a given carat weight, because it has higher specific gravity (3.73 vs. 3.52 - this means it's "heavier" compared to Diamond 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.


0.25 Ct Alexandrite (Round) 0.25 Ct Diamond (Round)
3.85×3.85 mm vs 4.09×4.09 mm
11.64 mm²   13.14 mm²
Face-up size outline for 0.25ct Diamond (4.09×4.09mm, round cut)
Face-up size outline for 0.25ct Alexandrite (3.85×3.85mm, round cut)
0.25ct Alexandrite Round (3.85×3.85mm)
0.25ct Diamond Round (4.09×4.09mm)
Difference: 13% (1.5 mm²)
0.25ct Diamond (Round, 4.09×4.09mm) has approx. 13% more face-up area than 0.25ct Alexandrite (Round, 3.85×3.85mm).


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