×
carat vs. color  length*  width*
  ×

(or examine a )
* size in mm (optional)

0.25ct Alexandrite (Cabochon, 4.41×2.94mm, Bluish Green) vs 0.25ct Diamond (Cabochon, 4.5×3mm, White)


Quick summary: When looked from above (face-up position), 0.25ct Diamond (4.5×3mm, cabochon cut) appears 4% larger than 0.25ct Alexandrite (4.41×2.94mm, cabochon cut). See below how they compare side-by-side on a ring and finger.

0.25ct Alexandrite (cabochon cut)
vs
 0.25ct Diamond (cabochon cut)
bluish green
 
white
4.41×2.94 mm 4.5×3 mm
actual size
Actual size of 0.25ct Alexandrite (cabochon cut, 4.41×2.94mm, Bluish Green color)   Actual size of 0.25ct Diamond (cabochon cut, 4.5×3mm, 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 (cabochon cut, 4.41×2.94mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
White 0.25ct Diamond (cabochon cut, 4.5×3mm) 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
 18% vs 18%
Saved...
Ring diameter: 16.9 mm
USA UK Asia EU1 EU2
Actual sizes of 0.25ct Alexandrite Cabochon (4.41×2.94mm, Bluish Green) and 0.25ct Diamond Cabochon (4.5×3mm, 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 (Cabochon) 0.25 Ct Diamond (Cabochon)
4.41×2.94 mm vs 4.5×3 mm
10.63 mm²   11.07 mm²
Face-up size outline for 0.25ct Diamond (4.5×3mm, cabochon cut)
Face-up size outline for 0.25ct Alexandrite (4.41×2.94mm, cabochon cut)
0.25ct Alexandrite Cabochon (4.41×2.94mm)
0.25ct Diamond Cabochon (4.5×3mm)
Difference: 4% (0.44 mm²)
0.25ct Diamond (Cabochon, 4.5×3mm) has approx. 4% more face-up area than 0.25ct Alexandrite (Cabochon, 4.41×2.94mm).


Popular comparisons: