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20ct Tanzanite (Cabochon, 19.71×13.14mm, Blue) vs 20ct Aquamarine (Cabochon, 21.12×14.08mm, Light Blue)


Quick summary: When looked from above (face-up position), 20ct Aquamarine (21.12×14.08mm, cabochon cut) appears 15% larger than 20ct Tanzanite (19.71×13.14mm, cabochon cut). See below how they compare side-by-side on a ring and finger.

20ct Tanzanite (cabochon cut)
vs
20ct Aquamarine (cabochon cut)
blue
 
light blue
19.71×13.14 mm 21.12×14.08 mm
actual size
Actual size of 20ct Tanzanite (cabochon cut, 19.71×13.14mm, Blue color)   Actual size of 20ct Aquamarine (cabochon cut, 21.12×14.08mm, Light Blue color)
 
Actual size is set for screen
Ring: Skin tone:
Ring width: 3.0 mm
Left finger image
Ring on left finger
Blue 20ct Tanzanite (cabochon cut, 19.71×13.14mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Light Blue 20ct Aquamarine (cabochon cut, 21.12×14.08mm) 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
78% vs 84%
Saved...
Ring diameter: 16.9 mm
USA UK Asia EU1 EU2
Actual sizes of 20ct Tanzanite Cabochon (19.71×13.14mm, Blue) and 20ct Aquamarine Cabochon (21.12×14.08mm, Light 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 Aquamarine for a given carat weight, because it has higher specific gravity (3.35 vs. 2.72 - this means it's "heavier" compared to Aquamarine 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.


20 Ct Tanzanite (Cabochon) 20 Ct Aquamarine (Cabochon)
19.71×13.14 mm vs 21.12×14.08 mm
212.37 mm²   243.84 mm²
Face-up size outline for 20ct Aquamarine (21.12×14.08mm, cabochon cut)
Face-up size outline for 20ct Tanzanite (19.71×13.14mm, cabochon cut)
20ct Tanzanite Cabochon (19.71×13.14mm)
20ct Aquamarine Cabochon (21.12×14.08mm)
Difference: 15% (31.47 mm²)
20ct Aquamarine (Cabochon, 21.12×14.08mm) has approx. 15% more face-up area than 20ct Tanzanite (Cabochon, 19.71×13.14mm).


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