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8ct Amethyst (Trillion, 16.77×16.77mm, Violet) vs 8ct Tanzanite (Trillion, 15.51×15.51mm, Blue)


Quick summary: When looked from above (face-up position), 8ct Amethyst (16.77×16.77mm, trillion cut) appears 17% larger than 8ct Tanzanite (15.51×15.51mm, trillion cut). See below how they compare side-by-side on a ring and finger.

8ct Amethyst (trillion cut)
vs
8ct Tanzanite (trillion cut)
violet
 
blue
16.77×16.77 mm 15.51×15.51 mm
actual size
Actual size of 8ct Amethyst (trillion cut, 16.77×16.77mm, Violet color)   Actual size of 8ct Tanzanite (trillion cut, 15.51×15.51mm, Blue color)
 
Actual size is set for screen
Ring: Skin tone:
Ring width: 3.0 mm
Left finger image
Ring on left finger
Violet 8ct Amethyst (trillion cut, 16.77×16.77mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Blue 8ct Tanzanite (trillion cut, 15.51×15.51mm) 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
100% vs 92%
Saved...
Ring diameter: 16.9 mm
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Actual sizes of 8ct Amethyst Trillion (16.77×16.77mm, Violet) and 8ct Tanzanite Trillion (15.51×15.51mm, Blue) 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, Tanzanite will face-up smaller than Amethyst for a given carat weight, because it has higher specific gravity (3.35 vs. 2.65 - this means it's "heavier" compared to Amethyst 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 Amethyst (Trillion) 8 Ct Tanzanite (Trillion)
16.77×16.77 mm vs 15.51×15.51 mm
174.36 mm²   149.15 mm²
Face-up size outline for 8ct Amethyst (16.77×16.77mm, trillion cut)
Face-up size outline for 8ct Tanzanite (15.51×15.51mm, trillion cut)
8ct Amethyst Trillion (16.77×16.77mm)
8ct Tanzanite Trillion (15.51×15.51mm)
Difference: 17% (25.21 mm²)
8ct Amethyst (Trillion, 16.77×16.77mm) has approx. 17% more face-up area than 8ct Tanzanite (Trillion, 15.51×15.51mm).


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