How big is a 1 carat alexandrite?
By HeyGema™ · Updated
In short
A 1 carat round alexandrite measures about 6.3 mm across (0.25 inches), 2% narrower than a 1 carat diamond (6.5 mm). An oval of the same weight is 7.8 x 5.4 mm and an emerald cut 6.9 x 4.9 mm.
- 6.3 mmround alexandrite, across
- 0.25 inthe same in inches
- 0.20 gweight
- 38%of a size 6 finger's width
Carat to mm calculator
About 6.3 x 6.3 mm
An estimate for a well-cut stone. A deep or shallow cut faces up smaller or bigger.
Round
6.3 mm
Oval
7.8 x 5.4 mm
Cushion
5.5 x 5.5 mm
Princess
5.4 x 5.4 mm
Emerald cut
6.9 x 4.9 mm
Asscher
5.4 x 5.4 mm
Radiant
6.4 x 4.9 mm
Pear
8.3 x 5.4 mm
Marquise
10.2 x 5.1 mm
Heart
6.4 x 6.4 mm
Trillion
6.9 x 6.9 mm
Baguette
7.8 x 3.9 mm
= 2 mm in every picture above
1 carat alexandrite size by shape
Face-up measurements of a well-cut 1 carat alexandrite. Alexandrite is denser than diamond (3.73 against 3.52), so it packs more weight into less space and faces up 2% narrower for the same weight.
- Round
- Length x width: 6.3 mm
- In inches: 0.25 in
- Oval
- Length x width: 7.8 x 5.4 mm
- In inches: 0.31 x 0.21 in
- Cushion
- Length x width: 5.5 x 5.5 mm
- In inches: 0.22 x 0.22 in
- Princess
- Length x width: 5.4 x 5.4 mm
- In inches: 0.21 x 0.21 in
- Emerald cut
- Length x width: 6.9 x 4.9 mm
- In inches: 0.27 x 0.19 in
- Asscher
- Length x width: 5.4 x 5.4 mm
- In inches: 0.21 x 0.21 in
- Radiant
- Length x width: 6.4 x 4.9 mm
- In inches: 0.25 x 0.19 in
- Pear
- Length x width: 8.3 x 5.4 mm
- In inches: 0.33 x 0.21 in
- Marquise
- Length x width: 10.2 x 5.1 mm
- In inches: 0.40 x 0.20 in
- Heart
- Length x width: 6.4 x 6.4 mm
- In inches: 0.25 x 0.25 in
- Trillion
- Length x width: 6.9 x 6.9 mm
- In inches: 0.27 x 0.27 in
- Baguette
- Length x width: 7.8 x 3.9 mm
- In inches: 0.31 x 0.15 in
1 carat alexandrite against other gems
- Diamond
- Round, 1 carat: 6.5 mm
- Moissanite
- Round, 1 carat: 6.6 mm
- Sapphire
- Round, 1 carat: 6.2 mm
- Ruby
- Round, 1 carat: 6.2 mm
- Emerald
- Round, 1 carat: 7.0 mm
- Aquamarine
- Round, 1 carat: 7.0 mm
- Morganite
- Round, 1 carat: 7.0 mm
- Tanzanite
- Round, 1 carat: 6.6 mm
- Alexandrite (this page)
- Round, 1 carat: 6.3 mm
1 carat alexandrite on a finger
- 4
- Finger width: 14.9 mm
- Round covers: 43%
- Oval covers: 36%
- 5
- Finger width: 15.7 mm
- Round covers: 40%
- Oval covers: 34%
- 6
- Finger width: 16.5 mm
- Round covers: 38%
- Oval covers: 33%
- 7
- Finger width: 17.3 mm
- Round covers: 37%
- Oval covers: 31%
- 8
- Finger width: 18.1 mm
- Round covers: 35%
- Oval covers: 30%
- 9
- Finger width: 18.9 mm
- Round covers: 33%
- Oval covers: 28%
Alexandrite at nearby weights
- 0.5 carat alexandrite
- Round diameter: 5.0 mm
- 1 ct (this page)
- Round diameter: 6.3 mm
- 1.5 carat alexandrite
- Round diameter: 7.2 mm
Questions
A round 1 carat alexandrite is about 6.3 mm across. Other shapes are longer than they are wide: an oval is 7.8 x 5.4 mm.
No. A round 1 carat alexandrite is 2% narrower than a 1 carat diamond (6.5 mm).
0.20 grams. A carat is 200 milligrams for every gem.
A round 1 carat alexandrite covers 38% of the width of a size 6 finger. Compare it with a ring you have tried on in the finger chart above.