20 Carat Alexandrite (Round, 16.61mm, Bluish Green)
Color:
Actual size is set for screen
How big is a 20 carat round-cut Alexandrite?
It depends on the cut proportions, but typically a 20ct round-cut Alexandrite would measure around 16.61 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 | |
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Ring |
Gold |
Skin tone |
Light |
Ring diameter |
16.9 mm |
Ring width |
3.0 mm |
Finger length |
64 mm |
Finger coverage |
99 % |
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Saved...
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Ring diameter:
16.9 mm
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Additional Info
Named after Czar Alexander II (1818-1881) Alexandrite is a rare and valuable color-change variety of chrysoberyl. Alexandrite possesses a surprising ability to change color - from green or bluish-green in daylight, it transforms to purplish or raspberry red in incandescent light.
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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Alexandrite |
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Mineral Group:
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Chrysoberyl |
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Shape:
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Round |
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Chemical Formula:
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BeAl2O4 |
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Crystal Structure:
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Orthorhombic |
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Hardness:
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8.5 |
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Specific Gravity
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3.73 |
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Carat weight:
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20 ct |
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Gram weight:
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4 g (0.1411 ounces) |
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Points:
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2000 pts |
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Length:
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16.61 mm |
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Width:
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16.61 mm |
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Average diameter:
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16.61 mm |
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Est. face-up size:
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216.69 mm² |
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Volume:
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1072.39 mm³ |
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Length-to-width ratio:
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1 |
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Refractive Index:
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1.744 - 1.755 |
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Luster:
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Vitreous |
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Wearability:
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Durable gem for daily wear |
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Care Instructions:
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No special or unusual care |
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Color:
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Alexandrite can be found in the following colors:
                  
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Birthstone:
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Alexandrite is a birthstone for the month of June |
Popular comparisons:
- 1ct Alexandrite (Round, Bluish Green, 6.14 x 6.14) vs. 1ct Emerald (Emerald, Green, 7.28 x 5.39)
- 1ct Alexandrite (Round, Bluish Green, 6.14 x 6.14) vs. 1ct Emerald (Emerald, Yellowish Green, 7.28 x 5.39)
- 1ct Alexandrite (Round, Bluish Green, 6.14 x 6.14) vs. 1ct Diamond (Round, White, 6.5 x 6.5)
- 0.2ct Alexandrite (Round, Bluish Green, 3.59 x 3.59) vs. 0.1ct Emerald (Emerald, Green, 3.38 x 2.5)
- 1ct Alexandrite (Round, Dark Bluish Green, 6.5 x 6.5) vs. 1ct Diamond (Round, White, 6.5 x 6.5)
- 1ct Alexandrite (Round, Bluish Green, 6.14 x 6.14) vs. 1ct Emerald (Round, Green, 6.82 x 6.82)
- 1ct Alexandrite (Round, Bluish Green, 6.14 x 6.14) vs. 1ct Emerald (Cushion, Green, 6.37 x 6.37)
- 1ct Alexandrite (Round, Bluish Green, 6.14 x 6.14) vs. 1ct Diamond (Emerald, White, 6.68 x 4.95)