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18ct Sapphire (Emerald, 16.74×12.4mm, Blue) vs 12ct Quartz (Emerald, 16.77×12.42mm, Blue)


Quick summary: When looked from above (face-up position), 12ct Quartz (16.77×12.42mm, emerald cut) appears 0.3% larger than 18ct Sapphire (16.74×12.4mm, emerald cut). See below how they compare side-by-side on a ring and finger.

18ct Sapphire (emerald cut)
vs
 12ct Quartz (emerald cut)
blue
 
blue
16.74×12.4 mm 16.77×12.42 mm
actual size
Actual size of 18ct Sapphire (emerald cut, 16.74×12.4mm, Blue color)   Actual size of 12ct Quartz (emerald cut, 16.77×12.42mm, 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 Sapphire (emerald cut, 16.74×12.4mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Blue 12ct Quartz (emerald cut, 16.77×12.42mm) 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
 74% vs 74%
Saved...
Ring diameter: 16.9 mm
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Actual sizes of 18ct Sapphire Emerald (16.74×12.4mm, Blue) and 12ct Quartz Emerald (16.77×12.42mm, 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 Quartz for a given carat weight, because it has higher specific gravity (4 vs. 2.65 - this means it's "heavier" compared to Quartz 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 (Emerald) 12 Ct Quartz (Emerald)
16.74×12.4 mm vs 16.77×12.42 mm
193.05 mm²   193.7 mm²
Face-up size outline for 12ct Quartz (16.77×12.42mm, emerald cut)
Face-up size outline for 18ct Sapphire (16.74×12.4mm, emerald cut)
18ct Sapphire Emerald (16.74×12.4mm)
12ct Quartz Emerald (16.77×12.42mm)
Difference: 0.3% (0.65 mm²)
12ct Quartz (Emerald, 16.77×12.42mm) has approx. 0.3% more face-up area than 18ct Sapphire (Emerald, 16.74×12.4mm).


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