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6ct Tanzanite (Emerald, 12.37×9.16mm, Blue) vs 6ct Alexandrite (Emerald, 11.91×8.82mm, Light Green )


Quick summary: When looked from above (face-up position), 6ct Tanzanite (12.37×9.16mm, emerald cut) appears 8% larger than 6ct Alexandrite (11.91×8.82mm, emerald cut). See below how they compare side-by-side on a ring and finger.

6ct Tanzanite (emerald cut)
vs
6ct Alexandrite (emerald cut)
blue
 
light green
12.37×9.16 mm 11.91×8.82 mm
actual size
Actual size of 6ct Tanzanite (emerald cut, 12.37×9.16mm, Blue color)   Actual size of 6ct Alexandrite (emerald cut, 11.91×8.82mm, Light Green  color)
 
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Left finger image
Ring on left finger
Blue 6ct Tanzanite (emerald cut, 12.37×9.16mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Light Green  6ct Alexandrite (emerald cut, 11.91×8.82mm) on a right ring and finger
Your settings
Ring
Gold
Skin tone
Light
Ring diameter
16.9 mm
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Finger length
64 mm
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Ring diameter: 16.9 mm
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Actual sizes of 6ct Tanzanite Emerald (12.37×9.16mm, Blue) and 6ct Alexandrite Emerald (11.91×8.82mm, Light 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 Tanzanite for a given carat weight, because it has higher specific gravity (3.7 vs. 3.3 - this means it's "heavier" compared to Tanzanite 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.


6 Ct Tanzanite (Emerald) 6 Ct Alexandrite (Emerald)
12.37×9.16 mm vs 11.91×8.82 mm
105.38 mm²   97.69 mm²
Face-up size outline for 6ct Tanzanite (12.37×9.16mm, emerald cut)
Face-up size outline for 6ct Alexandrite (11.91×8.82mm, emerald cut)
6ct Tanzanite Emerald (12.37×9.16mm)
6ct Alexandrite Emerald (11.91×8.82mm)
Difference: 8% (7.69 mm²)
6ct Tanzanite Emerald (12.37×9.16mm) has approx. 8% more face-up area than 6ct Alexandrite Emerald (11.91×8.82mm).


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