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4ct Spinel (Trillion, 12.02×12.02mm, Red) vs 4ct Alexandrite (Trillion, 11.88×11.88mm, Bluish Green)


Quick summary: When looked from above (face-up position), 4ct Spinel (12.02×12.02mm, trillion cut) appears 2% larger than 4ct Alexandrite (11.88×11.88mm, trillion cut). See below how they compare side-by-side on a ring and finger.

4ct Spinel (trillion cut)
vs
 4ct Alexandrite (trillion cut)
red
 
bluish green
12.02×12.02 mm 11.88×11.88 mm
actual size
Actual size of 4ct Spinel (trillion cut, 12.02×12.02mm, Red color)   Actual size of 4ct Alexandrite (trillion cut, 11.88×11.88mm, 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 4ct Spinel (trillion cut, 12.02×12.02mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Bluish Green 4ct Alexandrite (trillion cut, 11.88×11.88mm) 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
 72% vs 71%
Saved...
Ring diameter: 16.9 mm
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Actual sizes of 4ct Spinel Trillion (12.02×12.02mm, Red) and 4ct Alexandrite Trillion (11.88×11.88mm, 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 Ct Spinel (Trillion) 4 Ct Alexandrite (Trillion)
12.02×12.02 mm vs 11.88×11.88 mm
89.58 mm²   87.5 mm²
Face-up size outline for 4ct Spinel (12.02×12.02mm, trillion cut)
Face-up size outline for 4ct Alexandrite (11.88×11.88mm, trillion cut)
4ct Spinel Trillion (12.02×12.02mm)
4ct Alexandrite Trillion (11.88×11.88mm)
Difference: 2% (2.08 mm²)
4ct Spinel (Trillion, 12.02×12.02mm) has approx. 2% more face-up area than 4ct Alexandrite (Trillion, 11.88×11.88mm).


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