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4.5ct Spinel (Marquise, 16.62×8.31mm, Red) vs 4.5ct Alexandrite (Marquise, 16.44×8.22mm, Bluish Green)


Quick summary: When looked from above (face-up position), 4.5ct Spinel (16.62×8.31mm, marquise cut) appears 2% larger than 4.5ct Alexandrite (16.44×8.22mm, marquise cut). See below how they compare side-by-side on a ring and finger.

4.5ct Spinel (marquise cut)
vs
4.5ct Alexandrite (marquise cut)
red
 
bluish green
16.62×8.31 mm 16.44×8.22 mm
actual size
Actual size of 4.5ct Spinel (marquise cut, 16.62×8.31mm, Red color)   Actual size of 4.5ct Alexandrite (marquise cut, 16.44×8.22mm, 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 4.5ct Spinel (marquise cut, 16.62×8.31mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Bluish Green 4.5ct Alexandrite (marquise cut, 16.44×8.22mm) 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
50% vs 49%
Saved...
Ring diameter: 16.9 mm
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Actual sizes of 4.5ct Spinel Marquise (16.62×8.31mm, Red) and 4.5ct Alexandrite Marquise (16.44×8.22mm, 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.


4.5 Ct Spinel (Marquise) 4.5 Ct Alexandrite (Marquise)
16.62×8.31 mm vs 16.44×8.22 mm
98.06 mm²   95.95 mm²
Face-up size outline for 4.5ct Spinel (16.62×8.31mm, marquise cut)
Face-up size outline for 4.5ct Alexandrite (16.44×8.22mm, marquise cut)
4.5ct Spinel Marquise (16.62×8.31mm)
4.5ct Alexandrite Marquise (16.44×8.22mm)
Difference: 2% (2.11 mm²)
4.5ct Spinel (Marquise, 16.62×8.31mm) has approx. 2% more face-up area than 4.5ct Alexandrite (Marquise, 16.44×8.22mm).


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