28ct Alexandrite (Cushion, 17.2×17.2mm, Bluish Green) vs 28ct Topaz (Cushion, 17.52×17.52mm, Blue)
Quick summary: When looked from above (face-up position), 28ct Topaz (17.52×17.52mm, cushion cut) appears 4% larger than 28ct Alexandrite (17.2×17.2mm, cushion cut). See below how they compare side-by-side on a ring and finger.
| 28ct Alexandrite (cushion cut) |
vs
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28ct Topaz (cushion cut) |
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bluish green |
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| 17.2×17.2 mm | 17.52×17.52 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
28ct Alexandrite Cushion (17.2×17.2mm, Bluish Green)
and
28ct Topaz Cushion (17.52×17.52mm, 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, Alexandrite will face-up smaller than Topaz for a given
carat weight, because it has higher specific gravity
(3.73 vs. 3.53 - this means it's "heavier" compared to Topaz 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.
| 28 Ct Alexandrite (Cushion) | 28 Ct Topaz (Cushion) | |
| 17.2×17.2 mm | vs | 17.52×17.52 mm |
| 266.26 mm² | 276.26 mm² |
| 28ct Alexandrite Cushion (17.2×17.2mm) | |
| 28ct Topaz Cushion (17.52×17.52mm) | |
| Difference: 4% (10 mm²) |
28ct Topaz (Cushion, 17.52×17.52mm) has approx. 4% more face-up area than 28ct Alexandrite (Cushion, 17.2×17.2mm).
Popular comparisons:
- 1ct Alexandrite (Cushion, Bluish Green, 5.74 x 5.74) vs. 1ct Emerald (Emerald, Green, 7.28 x 5.39)
- 7.75ct Alexandrite (Cushion, Dark Bluish Green, 11 x 11) vs. 8.5ct Alexandrite (Oval, Dark Bluish Green, 14 x 10)
- 3ct Alexandrite (Cushion, Bluish Green, 8.28 x 8.28) vs. 3ct Diamond (Round, White, 9.37 x 9.37)
- 2.98ct Alexandrite (Cushion, Dark Violet, 9.5 x 7.1) vs. 1.54ct Diamond (Oval, Bluish Green, 9.65 x 6.42)
- 1ct Alexandrite (Cushion, Bluish Green, 5.5 x 5.5) vs. 1ct Topaz (Round, Dark Bluish Green, 6 x 6)
- 0.7ct Alexandrite (Cushion, Bluish Green, 5 x 5) vs. 0.7ct Topaz (Round, Bluish Green, 6 x 6)
- 1ct Alexandrite (Cushion, Light Purple, 5.5 x 5.5) vs. 1ct Alexandrite (Round, Dark Bluish Green, 6 x 6)
- 1.2ct Alexandrite (Cushion, Bluish Green, 6 x 6) vs. 1.45ct Alexandrite (Pear, Bluish Green, 8 x 6)
- 2ct Alexandrite (Cushion, Dark Violet, 8 x 8) vs. 1.54ct Diamond (Oval, Bluish Green, 9.65 x 6.42)