18 Carat Sapphire (Round, 15.67mm, Blue)
Color:
Actual size is set for screen
How big is an 18 carat round-cut Sapphire?
It depends on the cut proportions, but typically an 18ct round-cut Sapphire would measure around 15.67 mm (±4%) in diameter. You can check the finger coverage in the simulator below.
Ring:
Skin tone:
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Ring width:
3.0 mm
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Saved...
64 mm
| Your settings | |
|---|---|
Ring |
Gold |
Skin tone |
Light |
Ring diameter |
16.9 mm |
Ring width |
3.0 mm |
Finger length |
64 mm |
Finger coverage |
93 % |
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Saved...
|
|
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Ring diameter:
16.9 mm
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Additional Info
Sapphire got its name from the Greek word "sappheiros", which means "blue stone". Today, most people still associate Sapphires with the color blue, however, any gemstone quality Corundum that is not red (Ruby) is actually called Sapphire.
Where to buy?
For certified gemstones, high-end gemstone jewelry, and birthstone jewelry, see Blue Nile
Gem Details
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Name:
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Sapphire |
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Mineral Group:
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Corundum |
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Shape:
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Round |
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Chemical Formula:
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Al2O3 |
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Crystal Structure:
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Hexagonal |
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Hardness:
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9 |
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Specific Gravity
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4 |
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Carat weight:
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18 ct |
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Gram weight:
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3.6 g (0.127 ounces) |
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Points:
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1800 pts |
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Length:
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15.67 mm |
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Width:
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15.67 mm |
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Average diameter:
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15.67 mm |
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Est. face-up size:
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192.85 mm² |
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Volume:
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900 mm³ |
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Length-to-width ratio:
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1 |
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Refractive Index:
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1.76 - 1.77 |
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Luster:
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Vitreous to adamantine |
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Wearability:
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Excellent |
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Care Instructions:
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No special or unusual care |
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Color:
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Sapphire can be found in the following colors:
                           
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Birthstone:
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Sapphire is a birthstone for the month of September |
Popular comparisons:
- 18ct Sapphire (Round, Blue, 15.67 x 15.67) vs. 5ct Ruby (Round, Red, 10.22 x 10.22)
- 1ct Sapphire (Round, Blue, 5.98 x 5.98) vs. 1ct Emerald (Emerald, Green, 7.28 x 5.39)
- 2ct Sapphire (Round, Blue, 7.53 x 7.53) vs. 2ct Diamond (Round, White, 8.19 x 8.19)
- 1ct Sapphire (Round, Blue, 6.5 x 6.5) vs. 1ct Sapphire (Cushion, Blue, 6 x 6)
- 5.55ct Sapphire (Round, Blue, 10.58 x 10.58) vs. 9ct Sapphire (Cushion, Blue, 11.63 x 11.63)
- 1ct Sapphire (Round, Blue, 5.98 x 5.98) vs. 1ct Diamond (Round, White, 6.5 x 6.5)
- 0.3ct Sapphire (Round, Yellow, 4 x 4) vs. 0.2ct Sapphire (Round, Blue, 3.5 x 3.5)
- 0.8ct Sapphire (Round, Blue, 5.55 x 5.55) vs. 0.6ct Sapphire (Cushion, Blue, 4.72 x 4.72)
Use the simulator on this page to play around with different ring and finger configurations.