How big is a 3 carat tanzanite?
By HeyGema™ · Updated
In short
A 3 carat round tanzanite measures about 9.5 mm across (0.37 inches), 2% wider than a 3 carat diamond (9.3 mm). An oval of the same weight is 11.7 x 8.1 mm and an emerald cut 10.3 x 7.3 mm.
- 9.5 mmround tanzanite, across
- 0.37 inthe same in inches
- 0.60 gweight
- 57%of a size 6 finger's width
Carat to mm calculator
About 9.5 x 9.5 mm
An estimate for a well-cut stone. A deep or shallow cut faces up smaller or bigger.
Round
9.5 mm
Oval
11.7 x 8.1 mm
Cushion
8.2 x 8.2 mm
Princess
8.1 x 8.1 mm
Emerald cut
10.3 x 7.3 mm
Asscher
8.1 x 8.1 mm
Radiant
9.5 x 7.3 mm
Pear
12.5 x 8.1 mm
Marquise
15.2 x 7.6 mm
Heart
9.5 x 9.5 mm
Trillion
10.3 x 10.3 mm
Baguette
11.7 x 5.9 mm
= 5 mm in every picture above
3 carat tanzanite size by shape
Face-up measurements of a well-cut 3 carat tanzanite. Tanzanite is lighter than diamond (3.35 against 3.52), so the same weight gives a bigger stone, 2% wider across.
- Round
- Length x width: 9.5 mm
- In inches: 0.37 in
- Oval
- Length x width: 11.7 x 8.1 mm
- In inches: 0.46 x 0.32 in
- Cushion
- Length x width: 8.2 x 8.2 mm
- In inches: 0.32 x 0.32 in
- Princess
- Length x width: 8.1 x 8.1 mm
- In inches: 0.32 x 0.32 in
- Emerald cut
- Length x width: 10.3 x 7.3 mm
- In inches: 0.40 x 0.29 in
- Asscher
- Length x width: 8.1 x 8.1 mm
- In inches: 0.32 x 0.32 in
- Radiant
- Length x width: 9.5 x 7.3 mm
- In inches: 0.38 x 0.29 in
- Pear
- Length x width: 12.5 x 8.1 mm
- In inches: 0.49 x 0.32 in
- Marquise
- Length x width: 15.2 x 7.6 mm
- In inches: 0.60 x 0.30 in
- Heart
- Length x width: 9.5 x 9.5 mm
- In inches: 0.38 x 0.38 in
- Trillion
- Length x width: 10.3 x 10.3 mm
- In inches: 0.40 x 0.40 in
- Baguette
- Length x width: 11.7 x 5.9 mm
- In inches: 0.46 x 0.23 in
3 carat tanzanite 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
- Topaz
- Round, 3 carat: 9.3 mm
- Tanzanite (this page)
- Round, 3 carat: 9.5 mm
3 carat tanzanite on a finger
- 4
- Finger width: 14.9 mm
- Round covers: 64%
- Oval covers: 54%
- 5
- Finger width: 15.7 mm
- Round covers: 60%
- Oval covers: 51%
- 6
- Finger width: 16.5 mm
- Round covers: 57%
- Oval covers: 49%
- 7
- Finger width: 17.3 mm
- Round covers: 55%
- Oval covers: 47%
- 8
- Finger width: 18.1 mm
- Round covers: 52%
- Oval covers: 44%
- 9
- Finger width: 18.9 mm
- Round covers: 50%
- Oval covers: 43%
Tanzanite at nearby weights
- 2 carat tanzanite
- Round diameter: 8.3 mm
- 3 ct (this page)
- Round diameter: 9.5 mm
- 4 carat tanzanite
- Round diameter: 10.4 mm
Questions
A round 3 carat tanzanite is about 9.5 mm across. Other shapes are longer than they are wide: an oval is 11.7 x 8.1 mm.
Yes. A round 3 carat tanzanite is 2% wider than a 3 carat diamond (9.3 mm).
0.60 grams. A carat is 200 milligrams for every gem.
A round 3 carat tanzanite covers 57% of the width of a size 6 finger. Compare it with a ring you have tried on in the finger chart above.