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18ct Tourmaline (Cushion, 15.86×15.86mm, Purple) vs 18ct Quartz (Cushion, 16.64×16.64mm, Brown)


Quick summary: When looked from above (face-up position), 18ct Quartz (16.64×16.64mm, cushion cut) appears 10% larger than 18ct Tourmaline (15.86×15.86mm, cushion cut). See below how they compare side-by-side on a ring and finger.

18ct Tourmaline (cushion cut)
vs
 18ct Quartz (cushion cut)
purple
 
brown
15.86×15.86 mm 16.64×16.64 mm
actual size
Actual size of 18ct Tourmaline (cushion cut, 15.86×15.86mm, Purple color)   Actual size of 18ct Quartz (cushion cut, 16.64×16.64mm, Brown color)
Actual size is set for screen
Ring: Skin tone:
Ring width: 3.0 mm
Left finger image
Ring on left finger
Purple 18ct Tourmaline (cushion cut, 15.86×15.86mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Brown 18ct Quartz (cushion cut, 16.64×16.64mm) 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
 94% vs 99%
Saved...
Ring diameter: 16.9 mm
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Actual sizes of 18ct Tourmaline Cushion (15.86×15.86mm, Purple) and 18ct Quartz Cushion (16.64×16.64mm, Brown) 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, Tourmaline will face-up smaller than Quartz for a given carat weight, because it has higher specific gravity (3.06 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 Tourmaline (Cushion) 18 Ct Quartz (Cushion)
15.86×15.86 mm vs 16.64×16.64 mm
226.39 mm²   249.2 mm²
Face-up size outline for 18ct Quartz (16.64×16.64mm, cushion cut)
Face-up size outline for 18ct Tourmaline (15.86×15.86mm, cushion cut)
18ct Tourmaline Cushion (15.86×15.86mm)
18ct Quartz Cushion (16.64×16.64mm)
Difference: 10% (22.81 mm²)
18ct Quartz (Cushion, 16.64×16.64mm) has approx. 10% more face-up area than 18ct Tourmaline (Cushion, 15.86×15.86mm).


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