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0.4ct Sapphire (Round, 4.4×4.4mm, Blue) vs 0.9ct Tanzanite (Round, 6.15×6.15mm, Blue)


Quick summary: When looked from above (face-up position), 0.9ct Tanzanite (6.15×6.15mm, round cut) appears 95% larger than 0.4ct Sapphire (4.4×4.4mm, round cut). See below how they compare side-by-side on a ring and finger.

0.4ct Sapphire (round cut)
vs
 0.9ct Tanzanite (round cut)
blue
 
blue
4.4×4.4 mm 6.15×6.15 mm
actual size
Actual size of 0.4ct Sapphire (round cut, 4.4×4.4mm, Blue color)   Actual size of 0.9ct Tanzanite (round cut, 6.15×6.15mm, Blue color)
 
Actual size is set for screen
Ring: Skin tone:
Ring width: 3.0 mm
Left finger image
Ring on left finger
Blue 0.4ct Sapphire (round cut, 4.4×4.4mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Blue 0.9ct Tanzanite (round cut, 6.15×6.15mm) 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
 27% vs 37%
Saved...
Ring diameter: 16.9 mm
USA UK Asia EU1 EU2
Actual sizes of 0.4ct Sapphire Round (4.4×4.4mm, Blue) and 0.9ct Tanzanite Round (6.15×6.15mm, 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, Sapphire will face-up smaller than Tanzanite for a given carat weight, because it has higher specific gravity (4 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.


0.4 Ct Sapphire (Round) 0.9 Ct Tanzanite (Round)
4.4×4.4 mm vs 6.15×6.15 mm
15.21 mm²   29.71 mm²
Face-up size outline for 0.9ct Tanzanite (6.15×6.15mm, round cut)
Face-up size outline for 0.4ct Sapphire (4.4×4.4mm, round cut)
0.4ct Sapphire Round (4.4×4.4mm)
0.9ct Tanzanite Round (6.15×6.15mm)
Difference: 95% (14.5 mm²)
0.9ct Tanzanite (Round, 6.15×6.15mm) has approx. 95% more face-up area than 0.4ct Sapphire (Round, 4.4×4.4mm).


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