How big is a 3 carat alexandrite?
By HeyGema™ · Updated
In short
A 3 carat round alexandrite measures about 9.1 mm across (0.36 inches), 2% narrower than a 3 carat diamond (9.3 mm). An oval of the same weight is 11.3 x 7.8 mm and an emerald cut 9.9 x 7.1 mm.
- 9.1 mmround alexandrite, across
- 0.36 inthe same in inches
- 0.60 gweight
- 55%of a size 6 finger's width
Carat to mm calculator
About 9.1 x 9.1 mm
An estimate for a well-cut stone. A deep or shallow cut faces up smaller or bigger.
Round
9.1 mm
Oval
11.3 x 7.8 mm
Cushion
7.9 x 7.9 mm
Princess
7.8 x 7.8 mm
Emerald cut
9.9 x 7.1 mm
Asscher
7.8 x 7.8 mm
Radiant
9.2 x 7.1 mm
Pear
12.0 x 7.8 mm
Marquise
14.7 x 7.4 mm
Heart
9.2 x 9.2 mm
Trillion
9.9 x 9.9 mm
Baguette
11.3 x 5.7 mm
= 5 mm in every picture above
3 carat alexandrite size by shape
Face-up measurements of a well-cut 3 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: 9.1 mm
- In inches: 0.36 in
- Oval
- Length x width: 11.3 x 7.8 mm
- In inches: 0.45 x 0.31 in
- Cushion
- Length x width: 7.9 x 7.9 mm
- In inches: 0.31 x 0.31 in
- Princess
- Length x width: 7.8 x 7.8 mm
- In inches: 0.31 x 0.31 in
- Emerald cut
- Length x width: 9.9 x 7.1 mm
- In inches: 0.39 x 0.28 in
- Asscher
- Length x width: 7.8 x 7.8 mm
- In inches: 0.31 x 0.31 in
- Radiant
- Length x width: 9.2 x 7.1 mm
- In inches: 0.36 x 0.28 in
- Pear
- Length x width: 12.0 x 7.8 mm
- In inches: 0.47 x 0.31 in
- Marquise
- Length x width: 14.7 x 7.4 mm
- In inches: 0.58 x 0.29 in
- Heart
- Length x width: 9.2 x 9.2 mm
- In inches: 0.36 x 0.36 in
- Trillion
- Length x width: 9.9 x 9.9 mm
- In inches: 0.39 x 0.39 in
- Baguette
- Length x width: 11.3 x 5.7 mm
- In inches: 0.45 x 0.22 in
3 carat alexandrite against other gems
- Diamond
- Round, 3 carat: 9.3 mm
- Moissanite
- Round, 3 carat: 9.6 mm
- Sapphire
- Round, 3 carat: 8.9 mm
- Ruby
- Round, 3 carat: 8.9 mm
- Emerald
- Round, 3 carat: 10.1 mm
- Aquamarine
- Round, 3 carat: 10.2 mm
- Morganite
- Round, 3 carat: 10.0 mm
- Tanzanite
- Round, 3 carat: 9.5 mm
- Alexandrite (this page)
- Round, 3 carat: 9.1 mm
3 carat alexandrite on a finger
- 4
- Finger width: 14.9 mm
- Round covers: 61%
- Oval covers: 52%
- 5
- Finger width: 15.7 mm
- Round covers: 58%
- Oval covers: 50%
- 6
- Finger width: 16.5 mm
- Round covers: 55%
- Oval covers: 47%
- 7
- Finger width: 17.3 mm
- Round covers: 53%
- Oval covers: 45%
- 8
- Finger width: 18.1 mm
- Round covers: 50%
- Oval covers: 43%
- 9
- Finger width: 18.9 mm
- Round covers: 48%
- Oval covers: 41%
Alexandrite at nearby weights
- 2 carat alexandrite
- Round diameter: 8.0 mm
- 3 ct (this page)
- Round diameter: 9.1 mm
- 4 carat alexandrite
- Round diameter: 10.0 mm
Questions
A round 3 carat alexandrite is about 9.1 mm across. Other shapes are longer than they are wide: an oval is 11.3 x 7.8 mm.
No. A round 3 carat alexandrite is 2% narrower than a 3 carat diamond (9.3 mm).
0.60 grams. A carat is 200 milligrams for every gem.
A round 3 carat alexandrite covers 55% of the width of a size 6 finger. Compare it with a ring you have tried on in the finger chart above.