15ct Amethyst (Heart, 17.7×17.7mm, Violet) vs 15ct Alexandrite (Heart, 15.8×15.8mm, Bluish Green)
Quick summary: When looked from above (face-up position), 15ct Amethyst (17.7×17.7mm, heart cut) appears 25% larger than 15ct Alexandrite (15.8×15.8mm, heart cut). See below how they compare side-by-side on a ring and finger.
| 15ct Amethyst (heart cut) |
vs
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15ct Alexandrite (heart cut) |
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violet |
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| 17.7×17.7 mm | 15.8×15.8 mm | |
| actual size | ||
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Actual size is set for screen
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Ring:
Skin tone:
Ring width: 3.0 mm
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64 mm |
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Actual sizes of
15ct Amethyst Heart (17.7×17.7mm, Violet)
and
15ct Alexandrite Heart (15.8×15.8mm, 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, Alexandrite will face-up smaller than Amethyst for a given
carat weight, because it has higher specific gravity
(3.73 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.
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.
| 15 Ct Amethyst (Heart) | 15 Ct Alexandrite (Heart) | |
| 17.7×17.7 mm | vs | 15.8×15.8 mm |
| 225.57 mm² | 179.74 mm² |
| 15ct Amethyst Heart (17.7×17.7mm) | |
| 15ct Alexandrite Heart (15.8×15.8mm) | |
| Difference: 25% (45.83 mm²) |
15ct Amethyst (Heart, 17.7×17.7mm) has approx. 25% more face-up area than 15ct Alexandrite (Heart, 15.8×15.8mm).
Popular comparisons:
- 2.7ct Ruby (Pear, Red, 10 x 7) vs. 3ct Ruby (Emerald, Red, 9 x 7)
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- 6ct Morganite (Cushion, Light Red, 12 x 10) vs. 3.5ct Sapphire (Cushion, Blue, 8.49 x 8.49)
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- 1ct Sapphire (Baguette, Blue, 6.93 x 4.62) vs. 1ct Emerald (Emerald, Green, 7.28 x 5.39)
- 1ct Topaz (Round, Blue, 6 x 6) vs. 0.5ct Topaz (Round, Blue, 5 x 5)