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16ct Alexandrite (Trillion, 18.85×18.85mm, Bluish Green) vs 16ct Topaz (Trillion, 19.2×19.2mm, Blue)


Quick summary: When looked from above (face-up position), 16ct Topaz (19.2×19.2mm, trillion cut) appears 4% larger than 16ct Alexandrite (18.85×18.85mm, trillion cut). See below how they compare side-by-side on a ring and finger.

16ct Alexandrite (trillion cut)
vs
 16ct Topaz (trillion cut)
bluish green
 
blue
18.85×18.85 mm 19.2×19.2 mm
actual size
Actual size of 16ct Alexandrite (trillion cut, 18.85×18.85mm, Bluish Green color)   Actual size of 16ct Topaz (trillion cut, 19.2×19.2mm, Blue color)
 
Actual size is set for screen
Ring: Skin tone:
Ring width: 3.0 mm
Left finger image
Ring on left finger
Bluish Green 16ct Alexandrite (trillion cut, 18.85×18.85mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Blue 16ct Topaz (trillion cut, 19.2×19.2mm) 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
 112% vs 114%
Saved...
Ring diameter: 16.9 mm
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Actual sizes of 16ct Alexandrite Trillion (18.85×18.85mm, Bluish Green) and 16ct Topaz Trillion (19.2×19.2mm, 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.


16 Ct Alexandrite (Trillion) 16 Ct Topaz (Trillion)
18.85×18.85 mm vs 19.2×19.2 mm
220.3 mm²   228.56 mm²
Face-up size outline for 16ct Topaz (19.2×19.2mm, trillion cut)
Face-up size outline for 16ct Alexandrite (18.85×18.85mm, trillion cut)
16ct Alexandrite Trillion (18.85×18.85mm)
16ct Topaz Trillion (19.2×19.2mm)
Difference: 4% (8.26 mm²)
16ct Topaz (Trillion, 19.2×19.2mm) has approx. 4% more face-up area than 16ct Alexandrite (Trillion, 18.85×18.85mm).


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