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4.5ct Spinel (Round, 10.22×10.22mm, Red) vs 4.5ct Alexandrite (Round, 10.1×10.1mm, Bluish Green)


Quick summary: When looked from above (face-up position), 4.5ct Spinel (10.22×10.22mm, round cut) appears 2% larger than 4.5ct Alexandrite (10.1×10.1mm, round cut). See below how they compare side-by-side on a ring and finger.

4.5ct Spinel (round cut)
vs
 4.5ct Alexandrite (round cut)
red
 
bluish green
10.22×10.22 mm 10.1×10.1 mm
actual size
Actual size of 4.5ct Spinel (round cut, 10.22×10.22mm, Red color)   Actual size of 4.5ct Alexandrite (round cut, 10.1×10.1mm, 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 (round cut, 10.22×10.22mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Bluish Green 4.5ct Alexandrite (round cut, 10.1×10.1mm) 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
 61% vs 60%
Saved...
Ring diameter: 16.9 mm
USA UK Asia EU1 EU2
Actual sizes of 4.5ct Spinel Round (10.22×10.22mm, Red) and 4.5ct Alexandrite Round (10.1×10.1mm, 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 (Round) 4.5 Ct Alexandrite (Round)
10.22×10.22 mm vs 10.1×10.1 mm
82.03 mm²   80.12 mm²
Face-up size outline for 4.5ct Spinel (10.22×10.22mm, round cut)
Face-up size outline for 4.5ct Alexandrite (10.1×10.1mm, round cut)
4.5ct Spinel Round (10.22×10.22mm)
4.5ct Alexandrite Round (10.1×10.1mm)
Difference: 2% (1.91 mm²)
4.5ct Spinel (Round, 10.22×10.22mm) has approx. 2% more face-up area than 4.5ct Alexandrite (Round, 10.1×10.1mm).


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