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4ct Amethyst (Cabochon, 12.47×8.31mm, Violet) vs 0.35ct Sapphire (Round, 4.21×4.21mm, Blue)


Quick summary: When looked from above (face-up position), 4ct Amethyst (12.47×8.31mm, cabochon cut) appears 6.1 times larger than 0.35ct Sapphire (4.21×4.21mm, round cut). See below how they compare side-by-side on a ring and finger.

4ct Amethyst (cabochon cut)
vs
 0.35ct Sapphire (round cut)
violet
 
blue
12.47×8.31 mm 4.21×4.21 mm
actual size
Actual size of 4ct Amethyst (cabochon cut, 12.47×8.31mm, Violet color)   Actual size of 0.35ct Sapphire (round cut, 4.21×4.21mm, Blue color)
 
Actual size is set for screen
Ring: Skin tone:
Ring width: 3.0 mm
Left finger image
Ring on left finger
Violet 4ct Amethyst (cabochon cut, 12.47×8.31mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Blue 0.35ct Sapphire (round cut, 4.21×4.21mm) 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
 50% vs 25%
Saved...
Ring diameter: 16.9 mm
USA UK Asia EU1 EU2
Actual sizes of 4ct Amethyst Cabochon (12.47×8.31mm, Violet) and 0.35ct Sapphire Round (4.21×4.21mm, 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 Amethyst for a given carat weight, because it has higher specific gravity (4 vs. 2.65 - this means it's "heavier" compared to Amethyst 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.


4 Ct Amethyst (Cabochon) 0.35 Ct Sapphire (Round)
12.47×8.31 mm vs 4.21×4.21 mm
84.97 mm²   13.92 mm²
Face-up size outline for 4ct Amethyst (12.47×8.31mm, cabochon cut)
Face-up size outline for 0.35ct Sapphire (4.21×4.21mm, round cut)
4ct Amethyst Cabochon (12.47×8.31mm)
0.35ct Sapphire Round (4.21×4.21mm)
Difference: 510% (71.05 mm²)
4ct Amethyst (Cabochon, 12.47×8.31mm) has approx. 510% more face-up area than 0.35ct Sapphire (Round, 4.21×4.21mm). In other words, it's 6.1x larger.


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