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15ct Tanzanite (Cabochon, 17.91×11.94mm, Blue) vs 15ct Aquamarine (Cabochon, 19.2×12.8mm, Light Blue)


Quick summary: When looked from above (face-up position), 15ct Aquamarine (19.2×12.8mm, cabochon cut) appears 15% larger than 15ct Tanzanite (17.91×11.94mm, cabochon cut). See below how they compare side-by-side on a ring and finger.

15ct Tanzanite (cabochon cut)
vs
15ct Aquamarine (cabochon cut)
blue
 
light blue
17.91×11.94 mm 19.2×12.8 mm
actual size
Actual size of 15ct Tanzanite (cabochon cut, 17.91×11.94mm, Blue color)   Actual size of 15ct Aquamarine (cabochon cut, 19.2×12.8mm, 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 15ct Tanzanite (cabochon cut, 17.91×11.94mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Light Blue 15ct Aquamarine (cabochon cut, 19.2×12.8mm) 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
71% vs 76%
Saved...
Ring diameter: 16.9 mm
USA UK Asia EU1 EU2
Actual sizes of 15ct Tanzanite Cabochon (17.91×11.94mm, Blue) and 15ct Aquamarine Cabochon (19.2×12.8mm, 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.


15 Ct Tanzanite (Cabochon) 15 Ct Aquamarine (Cabochon)
17.91×11.94 mm vs 19.2×12.8 mm
175.35 mm²   201.52 mm²
Face-up size outline for 15ct Aquamarine (19.2×12.8mm, cabochon cut)
Face-up size outline for 15ct Tanzanite (17.91×11.94mm, cabochon cut)
15ct Tanzanite Cabochon (17.91×11.94mm)
15ct Aquamarine Cabochon (19.2×12.8mm)
Difference: 15% (26.17 mm²)
15ct Aquamarine (Cabochon, 19.2×12.8mm) has approx. 15% more face-up area than 15ct Tanzanite (Cabochon, 17.91×11.94mm).


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