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18ct Kyanite (Cabochon, 18.44×12.29mm, Blue) vs 18ct Sapphire (Cabochon, 17.94×11.96mm, Blue)


Quick summary: When looked from above (face-up position), 18ct Kyanite (18.44×12.29mm, cabochon cut) appears 6% larger than 18ct Sapphire (17.94×11.96mm, cabochon cut). See below how they compare side-by-side on a ring and finger.

18ct Kyanite (cabochon cut)
vs
18ct Sapphire (cabochon cut)
blue
 
blue
18.44×12.29 mm 17.94×11.96 mm
actual size
Actual size of 18ct Kyanite (cabochon cut, 18.44×12.29mm, Blue color)   Actual size of 18ct Sapphire (cabochon cut, 17.94×11.96mm, Blue color)
 
Actual size is set for screen
Ring: Skin tone:
Ring width: 3.0 mm
Left finger image
Ring on left finger
Blue 18ct Kyanite (cabochon cut, 18.44×12.29mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Blue 18ct Sapphire (cabochon cut, 17.94×11.96mm) 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
73% vs 71%
Saved...
Ring diameter: 16.9 mm
USA UK Asia EU1 EU2
Actual sizes of 18ct Kyanite Cabochon (18.44×12.29mm, Blue) and 18ct Sapphire Cabochon (17.94×11.96mm, 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 Kyanite for a given carat weight, because it has higher specific gravity (4 vs. 3.68 - this means it's "heavier" compared to Kyanite 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.


18 Ct Kyanite (Cabochon) 18 Ct Sapphire (Cabochon)
18.44×12.29 mm vs 17.94×11.96 mm
185.83 mm²   175.94 mm²
Face-up size outline for 18ct Kyanite (18.44×12.29mm, cabochon cut)
Face-up size outline for 18ct Sapphire (17.94×11.96mm, cabochon cut)
18ct Kyanite Cabochon (18.44×12.29mm)
18ct Sapphire Cabochon (17.94×11.96mm)
Difference: 6% (9.89 mm²)
18ct Kyanite (Cabochon, 18.44×12.29mm) has approx. 6% more face-up area than 18ct Sapphire (Cabochon, 17.94×11.96mm).


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