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0.25ct Kyanite (Cabochon, 4.44×2.96mm, Blue) vs 0.25ct Topaz (Cabochon, 4.5×3mm, Blue)


Quick summary: When looked from above (face-up position), 0.25ct Topaz (4.5×3mm, cabochon cut) appears 3% larger than 0.25ct Kyanite (4.44×2.96mm, cabochon cut). See below how they compare side-by-side on a ring and finger.

0.25ct Kyanite (cabochon cut)
vs
0.25ct Topaz (cabochon cut)
blue
 
blue
4.44×2.96 mm 4.5×3 mm
actual size
Actual size of 0.25ct Kyanite (cabochon cut, 4.44×2.96mm, Blue color)   Actual size of 0.25ct Topaz (cabochon cut, 4.5×3mm, Blue color)
 
Actual size is set for screen
Ring: Skin tone:
Ring width: 3.0 mm
Left finger image
Ring on left finger
Blue 0.25ct Kyanite (cabochon cut, 4.44×2.96mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Blue 0.25ct Topaz (cabochon cut, 4.5×3mm) 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
18% vs 18%
Saved...
Ring diameter: 16.9 mm
USA UK Asia EU1 EU2
Actual sizes of 0.25ct Kyanite Cabochon (4.44×2.96mm, Blue) and 0.25ct Topaz Cabochon (4.5×3mm, 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, Kyanite will face-up smaller than Topaz for a given carat weight, because it has higher specific gravity (3.68 vs. 3.53 - this means it's "heavier" compared to Topaz 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.


0.25 Ct Kyanite (Cabochon) 0.25 Ct Topaz (Cabochon)
4.44×2.96 mm vs 4.5×3 mm
10.78 mm²   11.07 mm²
Face-up size outline for 0.25ct Topaz (4.5×3mm, cabochon cut)
Face-up size outline for 0.25ct Kyanite (4.44×2.96mm, cabochon cut)
0.25ct Kyanite Cabochon (4.44×2.96mm)
0.25ct Topaz Cabochon (4.5×3mm)
Difference: 3% (0.29 mm²)
0.25ct Topaz (Cabochon, 4.5×3mm) has approx. 3% more face-up area than 0.25ct Kyanite (Cabochon, 4.44×2.96mm).


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