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18ct Sapphire (Marquise, 25.48×12.74mm, Blue) vs 18ct Fluorite (Marquise, 27.5×13.75mm, Bluish Green)


Quick summary: When looked from above (face-up position), 18ct Fluorite (27.5×13.75mm, marquise cut) appears 16% larger than 18ct Sapphire (25.48×12.74mm, marquise cut). See below how they compare side-by-side on a ring and finger.

18ct Sapphire (marquise cut)
vs
 18ct Fluorite (marquise cut)
blue
 
bluish green
25.48×12.74 mm 27.5×13.75 mm
actual size
Actual size of 18ct Sapphire (marquise cut, 25.48×12.74mm, Blue color)   Actual size of 18ct Fluorite (marquise cut, 27.5×13.75mm, Bluish Green color)
 
Actual size is set for screen
Ring: Skin tone:
Ring width: 3.0 mm
Left finger image
Ring on left finger
Blue 18ct Sapphire (marquise cut, 25.48×12.74mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Bluish Green 18ct Fluorite (marquise cut, 27.5×13.75mm) 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
 76% vs 82%
Saved...
Ring diameter: 16.9 mm
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Actual sizes of 18ct Sapphire Marquise (25.48×12.74mm, Blue) and 18ct Fluorite Marquise (27.5×13.75mm, Bluish Green) 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 Fluorite for a given carat weight, because it has higher specific gravity (4 vs. 3.18 - this means it's "heavier" compared to Fluorite 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 Sapphire (Marquise) 18 Ct Fluorite (Marquise)
25.48×12.74 mm vs 27.5×13.75 mm
230.48 mm²   268.47 mm²
Face-up size outline for 18ct Fluorite (27.5×13.75mm, marquise cut)
Face-up size outline for 18ct Sapphire (25.48×12.74mm, marquise cut)
18ct Sapphire Marquise (25.48×12.74mm)
18ct Fluorite Marquise (27.5×13.75mm)
Difference: 16% (37.99 mm²)
18ct Fluorite (Marquise, 27.5×13.75mm) has approx. 16% more face-up area than 18ct Sapphire (Marquise, 25.48×12.74mm).


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