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8ct Spinel (Marquise, 20.14×10.07mm, Red) vs 8ct Alexandrite (Marquise, 19.9×9.95mm, Bluish Green)


Quick summary: When looked from above (face-up position), 8ct Spinel (20.14×10.07mm, marquise cut) appears 2% larger than 8ct Alexandrite (19.9×9.95mm, marquise cut). See below how they compare side-by-side on a ring and finger.

8ct Spinel (marquise cut)
vs
8ct Alexandrite (marquise cut)
red
 
bluish green
20.14×10.07 mm 19.9×9.95 mm
actual size
Actual size of 8ct Spinel (marquise cut, 20.14×10.07mm, Red color)   Actual size of 8ct Alexandrite (marquise cut, 19.9×9.95mm, Bluish Green color)
Actual size is set for screen
Ring: Skin tone:
Ring width: 3.0 mm
Left finger image
Ring on left finger
Red 8ct Spinel (marquise cut, 20.14×10.07mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Bluish Green 8ct Alexandrite (marquise cut, 19.9×9.95mm) 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
60% vs 59%
Saved...
Ring diameter: 16.9 mm
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Actual sizes of 8ct Spinel Marquise (20.14×10.07mm, Red) and 8ct Alexandrite Marquise (19.9×9.95mm, 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 Spinel for a given carat weight, because it has higher specific gravity (3.73 vs. 3.6 - this means it's "heavier" compared to Spinel 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.


8 Ct Spinel (Marquise) 8 Ct Alexandrite (Marquise)
20.14×10.07 mm vs 19.9×9.95 mm
143.99 mm²   140.58 mm²
Face-up size outline for 8ct Spinel (20.14×10.07mm, marquise cut)
Face-up size outline for 8ct Alexandrite (19.9×9.95mm, marquise cut)
8ct Spinel Marquise (20.14×10.07mm)
8ct Alexandrite Marquise (19.9×9.95mm)
Difference: 2% (3.41 mm²)
8ct Spinel (Marquise, 20.14×10.07mm) has approx. 2% more face-up area than 8ct Alexandrite (Marquise, 19.9×9.95mm).


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