How big is a 3 carat tourmaline?
By HeyGema™ · Updated
In short
A 3 carat round tourmaline measures about 9.7 mm across (0.38 inches), 5% wider than a 3 carat diamond (9.3 mm). An oval of the same weight is 12.1 x 8.3 mm and an emerald cut 10.6 x 7.6 mm.
- 9.7 mmround tourmaline, across
- 0.38 inthe same in inches
- 0.60 gweight
- 59%of a size 6 finger's width
Carat to mm calculator
About 9.7 x 9.7 mm
An estimate for a well-cut stone. A deep or shallow cut faces up smaller or bigger.
Round
9.7 mm
Oval
12.1 x 8.3 mm
Cushion
8.5 x 8.5 mm
Princess
8.3 x 8.3 mm
Emerald cut
10.6 x 7.6 mm
Asscher
8.3 x 8.3 mm
Radiant
9.8 x 7.6 mm
Pear
12.8 x 8.3 mm
Marquise
15.7 x 7.9 mm
Heart
9.8 x 9.8 mm
Trillion
10.6 x 10.6 mm
Baguette
12.1 x 6.0 mm
= 5 mm in every picture above
3 carat tourmaline size by shape
Face-up measurements of a well-cut 3 carat tourmaline. Tourmaline is lighter than diamond (3.06 against 3.52), so the same weight gives a bigger stone, 5% wider across.
- Round
- Length x width: 9.7 mm
- In inches: 0.38 in
- Oval
- Length x width: 12.1 x 8.3 mm
- In inches: 0.48 x 0.33 in
- Cushion
- Length x width: 8.5 x 8.5 mm
- In inches: 0.33 x 0.33 in
- Princess
- Length x width: 8.3 x 8.3 mm
- In inches: 0.33 x 0.33 in
- Emerald cut
- Length x width: 10.6 x 7.6 mm
- In inches: 0.42 x 0.30 in
- Asscher
- Length x width: 8.3 x 8.3 mm
- In inches: 0.33 x 0.33 in
- Radiant
- Length x width: 9.8 x 7.6 mm
- In inches: 0.39 x 0.30 in
- Pear
- Length x width: 12.8 x 8.3 mm
- In inches: 0.51 x 0.33 in
- Marquise
- Length x width: 15.7 x 7.9 mm
- In inches: 0.62 x 0.31 in
- Heart
- Length x width: 9.8 x 9.8 mm
- In inches: 0.39 x 0.39 in
- Trillion
- Length x width: 10.6 x 10.6 mm
- In inches: 0.42 x 0.42 in
- Baguette
- Length x width: 12.1 x 6.0 mm
- In inches: 0.48 x 0.24 in
3 carat tourmaline 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
- Tourmaline (this page)
- Round, 3 carat: 9.7 mm
3 carat tourmaline on a finger
- 4
- Finger width: 14.9 mm
- Round covers: 65%
- Oval covers: 56%
- 5
- Finger width: 15.7 mm
- Round covers: 62%
- Oval covers: 53%
- 6
- Finger width: 16.5 mm
- Round covers: 59%
- Oval covers: 50%
- 7
- Finger width: 17.3 mm
- Round covers: 56%
- Oval covers: 48%
- 8
- Finger width: 18.1 mm
- Round covers: 54%
- Oval covers: 46%
- 9
- Finger width: 18.9 mm
- Round covers: 51%
- Oval covers: 44%
Tourmaline at nearby weights
- 2 carat tourmaline
- Round diameter: 8.5 mm
- 3 ct (this page)
- Round diameter: 9.7 mm
- 4 carat tourmaline
- Round diameter: 10.7 mm
Questions
A round 3 carat tourmaline is about 9.7 mm across. Other shapes are longer than they are wide: an oval is 12.1 x 8.3 mm.
Yes. A round 3 carat tourmaline is 5% wider than a 3 carat diamond (9.3 mm).
0.60 grams. A carat is 200 milligrams for every gem.
A round 3 carat tourmaline covers 59% of the width of a size 6 finger. Compare it with a ring you have tried on in the finger chart above.