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30ct Spinel (Round, 19.24×19.24mm, Red) vs 30ct Diamond (Round, 20.2×20.2mm, Light Gray)


Quick summary: When looked from above (face-up position), 30ct Colored Diamond (20.2×20.2mm, round cut) appears 10% larger than 30ct Spinel (19.24×19.24mm, round cut). See below how they compare side-by-side on a ring and finger.

30ct Spinel (round cut)
vs
 30ct Diamond (round cut)
red
 
light gray
19.24×19.24 mm 20.2×20.2 mm
actual size
Actual size of 30ct Spinel (round cut, 19.24×19.24mm, Red color)   Actual size of 30ct Diamond (round cut, 20.2×20.2mm, Light Gray color)
 
Actual size is set for screen
Ring: Skin tone:
Ring width: 3.0 mm
Left finger image
Ring on left finger
Red 30ct Spinel (round cut, 19.24×19.24mm) on a left ring and finger
64 mm
Right finger image
Ring on a right finger
Light Gray 30ct Diamond (round cut, 20.2×20.2mm) 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
 114% vs 120%
Saved...
Ring diameter: 16.9 mm
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Actual sizes of 30ct Spinel Round (19.24×19.24mm, Red) and 30ct Diamond Round (20.2×20.2mm, Light Gray) 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, Spinel will face-up slightly smaller than Diamond for a given carat weight, because it has higher specific gravity (3.6 vs. 3.52 - this means it's "slightly heavier" compared to Diamond 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.


30 Ct Spinel (Round) 30 Ct Colored Diamond (Round)
19.24×19.24 mm vs 20.2×20.2 mm
290.74 mm²   320.47 mm²
Face-up size outline for 30ct Diamond (20.2×20.2mm, round cut)
Face-up size outline for 30ct Spinel (19.24×19.24mm, round cut)
30ct Spinel Round (19.24×19.24mm)
30ct Colored Diamond Round (20.2×20.2mm)
Difference: 10% (29.73 mm²)
30ct Colored Diamond (Round, 20.2×20.2mm) has approx. 10% more face-up area than 30ct Spinel (Round, 19.24×19.24mm).


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