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1.5ct Tanzanite (Cabochon, 8.31×5.54mm, Blue) vs 1.5ct Topaz (Cabochon, 8.16×5.44mm, Blue)


Quick summary: When looked from above (face-up position), 1.5ct Tanzanite (8.31×5.54mm, cabochon cut) appears 4% larger than 1.5ct Topaz (8.16×5.44mm, cabochon cut). See below how they compare side-by-side on a ring and finger.

1.5ct Tanzanite (cabochon cut)
vs
1.5ct Topaz (cabochon cut)
blue
 
blue
8.31×5.54 mm 8.16×5.44 mm
actual size
Actual size of 1.5ct Tanzanite (cabochon cut, 8.31×5.54mm, Blue color)   Actual size of 1.5ct Topaz (cabochon cut, 8.16×5.44mm, Blue color)
 
Actual size is set for screen
Ring: Skin tone:
Ring width: 3.0 mm
Left finger image
Ring on left finger
Blue 1.5ct Tanzanite (cabochon cut, 8.31×5.54mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Blue 1.5ct Topaz (cabochon cut, 8.16×5.44mm) 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
33% vs 33%
Saved...
Ring diameter: 16.9 mm
USA UK Asia EU1 EU2
Actual sizes of 1.5ct Tanzanite Cabochon (8.31×5.54mm, Blue) and 1.5ct Topaz Cabochon (8.16×5.44mm, 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, Topaz will face-up smaller than Tanzanite for a given carat weight, because it has higher specific gravity (3.53 vs. 3.35 - 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.


1.5 Ct Tanzanite (Cabochon) 1.5 Ct Topaz (Cabochon)
8.31×5.54 mm vs 8.16×5.44 mm
37.75 mm²   36.4 mm²
Face-up size outline for 1.5ct Tanzanite (8.31×5.54mm, cabochon cut)
Face-up size outline for 1.5ct Topaz (8.16×5.44mm, cabochon cut)
1.5ct Tanzanite Cabochon (8.31×5.54mm)
1.5ct Topaz Cabochon (8.16×5.44mm)
Difference: 4% (1.35 mm²)
1.5ct Tanzanite (Cabochon, 8.31×5.54mm) has approx. 4% more face-up area than 1.5ct Topaz (Cabochon, 8.16×5.44mm).


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