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0.25ct Tourmaline (Round, 4.12×4.12mm, Purple) vs 0.25ct Topaz (Round, 3.93×3.93mm, Blue)


Quick summary: When looked from above (face-up position), 0.25ct Tourmaline (4.12×4.12mm, round cut) appears 10% larger than 0.25ct Topaz (3.93×3.93mm, round cut). See below how they compare side-by-side on a ring and finger.

0.25ct Tourmaline (round cut)
vs
 0.25ct Topaz (round cut)
purple
 
blue
4.12×4.12 mm 3.93×3.93 mm
actual size
Actual size of 0.25ct Tourmaline (round cut, 4.12×4.12mm, Purple color)   Actual size of 0.25ct Topaz (round cut, 3.93×3.93mm, Blue color)
 
Actual size is set for screen
Ring: Skin tone:
Ring width: 3.0 mm
Left finger image
Ring on left finger
Purple 0.25ct Tourmaline (round cut, 4.12×4.12mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Blue 0.25ct Topaz (round cut, 3.93×3.93mm) 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
 25% vs 24%
Saved...
Ring diameter: 16.9 mm
USA UK Asia EU1 EU2
Actual sizes of 0.25ct Tourmaline Round (4.12×4.12mm, Purple) and 0.25ct Topaz Round (3.93×3.93mm, 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, Topaz will face-up smaller than Tourmaline for a given carat weight, because it has higher specific gravity (3.53 vs. 3.06 - this means it's "heavier" compared to Tourmaline 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 Tourmaline (Round) 0.25 Ct Topaz (Round)
4.12×4.12 mm vs 3.93×3.93 mm
13.33 mm²   12.13 mm²
Face-up size outline for 0.25ct Tourmaline (4.12×4.12mm, round cut)
Face-up size outline for 0.25ct Topaz (3.93×3.93mm, round cut)
0.25ct Tourmaline Round (4.12×4.12mm)
0.25ct Topaz Round (3.93×3.93mm)
Difference: 10% (1.2 mm²)
0.25ct Tourmaline (Round, 4.12×4.12mm) has approx. 10% more face-up area than 0.25ct Topaz (Round, 3.93×3.93mm).


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