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2.5ct Tanzanite (Round, 8.65×8.65mm, Blue) vs 2.5ct Diamond (Round, 8.82×8.82mm, White)


Quick summary: When looked from above (face-up position), 2.5ct Diamond (8.82×8.82mm, round cut) appears 4% larger than 2.5ct Tanzanite (8.65×8.65mm, round cut). See below how they compare side-by-side on a ring and finger.

2.5ct Tanzanite (round cut)
vs
 2.5ct Diamond (round cut)
blue
 
white
8.65×8.65 mm 8.82×8.82 mm
actual size
Actual size of 2.5ct Tanzanite (round cut, 8.65×8.65mm, Blue color)   Actual size of 2.5ct Diamond (round cut, 8.82×8.82mm, White color)
 
Actual size is set for screen
Ring: Skin tone:
Ring width: 3.0 mm
Left finger image
Ring on left finger
Blue 2.5ct Tanzanite (round cut, 8.65×8.65mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
White 2.5ct Diamond (round cut, 8.82×8.82mm) 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
 52% vs 53%
Saved...
Ring diameter: 16.9 mm
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Actual sizes of 2.5ct Tanzanite Round (8.65×8.65mm, Blue) and 2.5ct Diamond Round (8.82×8.82mm, White) 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, Diamond will face-up smaller than Tanzanite for a given carat weight, because it has higher specific gravity (3.52 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.


2.5 Ct Tanzanite (Round) 2.5 Ct Diamond (Round)
8.65×8.65 mm vs 8.82×8.82 mm
58.77 mm²   61.1 mm²
Face-up size outline for 2.5ct Diamond (8.82×8.82mm, round cut)
Face-up size outline for 2.5ct Tanzanite (8.65×8.65mm, round cut)
2.5ct Tanzanite Round (8.65×8.65mm)
2.5ct Diamond Round (8.82×8.82mm)
Difference: 4% (2.33 mm²)
2.5ct Diamond (Round, 8.82×8.82mm) has approx. 4% more face-up area than 2.5ct Tanzanite (Round, 8.65×8.65mm).


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