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12ct Diaspore (Cabochon, 16.55×11.03mm, Light Yellowish Green) vs 12ct Alexandrite (Cabochon, 16.04×10.69mm, Bluish Green)


Quick summary: When looked from above (face-up position), 12ct Diaspore (16.55×11.03mm, cabochon cut) appears 6% larger than 12ct Alexandrite (16.04×10.69mm, cabochon cut). See below how they compare side-by-side on a ring and finger.

12ct Diaspore (cabochon cut)
vs
 12ct Alexandrite (cabochon cut)
light yellowish green
 
bluish green
16.55×11.03 mm 16.04×10.69 mm
actual size
Actual size of 12ct Diaspore (cabochon cut, 16.55×11.03mm, Light Yellowish Green color)   Actual size of 12ct Alexandrite (cabochon cut, 16.04×10.69mm, Bluish Green color)
Actual size is set for screen
Ring: Skin tone:
Ring width: 3.0 mm
Left finger image
Ring on left finger
Light Yellowish Green 12ct Diaspore (cabochon cut, 16.55×11.03mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Bluish Green 12ct Alexandrite (cabochon cut, 16.04×10.69mm) 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
 66% vs 64%
Saved...
Ring diameter: 16.9 mm
USA UK Asia EU1 EU2
Actual sizes of 12ct Diaspore Cabochon (16.55×11.03mm, Light Yellowish Green) and 12ct Alexandrite Cabochon (16.04×10.69mm, Bluish Green) 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 Diaspore for a given carat weight, because it has higher specific gravity (3.73 vs. 3.4 - this means it's "heavier" compared to Diaspore 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.


12 Ct Diaspore (Cabochon) 12 Ct Alexandrite (Cabochon)
16.55×11.03 mm vs 16.04×10.69 mm
149.69 mm²   140.6 mm²
Face-up size outline for 12ct Diaspore (16.55×11.03mm, cabochon cut)
Face-up size outline for 12ct Alexandrite (16.04×10.69mm, cabochon cut)
12ct Diaspore Cabochon (16.55×11.03mm)
12ct Alexandrite Cabochon (16.04×10.69mm)
Difference: 6% (9.09 mm²)
12ct Diaspore (Cabochon, 16.55×11.03mm) has approx. 6% more face-up area than 12ct Alexandrite (Cabochon, 16.04×10.69mm).


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