Turquoise size chart: carat to mm for every shape
By HeyGema™ · Updated
In short
A 1 carat round turquoise measures about 7.0 mm across, against 6.5 mm for a 1 carat diamond. Turquoise is lighter than diamond (2.76 against 3.52), so the same weight gives a bigger stone, 8% wider across.
- 7.0 mm1 carat round turquoise
- 2.76density, g/cm3
- 5 to 6hardness, Mohs
Carat to mm calculator
About 7.0 x 7.0 mm
An estimate for a well-cut stone. A deep or shallow cut faces up smaller or bigger.
Turquoise size chart: carat to mm
Face-up length and width in mm of a well-cut turquoise at each weight and shape. Turquoise is lighter than diamond (2.76 against 3.52), so the same weight gives a bigger stone, 8% wider across.
| Weight | Round | Oval | Cushion | Emerald cut | Pear | Princess |
|---|---|---|---|---|---|---|
| 0.25 ct | 4.4 | 5.5 x 3.8 | 3.8 x 3.8 | 4.8 x 3.4 | 5.8 x 3.8 | 3.8 x 3.8 |
| 0.5 ct | 5.6 | 6.9 x 4.7 | 4.8 x 4.8 | 6.0 x 4.3 | 7.3 x 4.7 | 4.7 x 4.7 |
| 0.75 ct | 6.4 | 7.9 x 5.4 | 5.5 x 5.5 | 6.9 x 4.9 | 8.4 x 5.4 | 5.4 x 5.4 |
| 1 ct | 7.0 | 8.7 x 6.0 | 6.1 x 6.1 | 7.6 x 5.4 | 9.2 x 6.0 | 6.0 x 6.0 |
| 1.5 ct | 8.0 | 9.9 x 6.8 | 7.0 x 7.0 | 8.7 x 6.2 | 10.6 x 6.8 | 6.8 x 6.8 |
| 2 ct | 8.8 | 10.9 x 7.5 | 7.7 x 7.7 | 9.6 x 6.8 | 11.6 x 7.5 | 7.5 x 7.5 |
| 3 ct | 10.1 | 12.5 x 8.6 | 8.8 x 8.8 | 10.9 x 7.8 | 13.3 x 8.6 | 8.6 x 8.6 |
| 4 ct | 11.1 | 13.8 x 9.5 | 9.6 x 9.6 | 12.1 x 8.6 | 14.6 x 9.5 | 9.5 x 9.5 |
| 5 ct | 12.0 | 14.8 x 10.2 | 10.4 x 10.4 | 13.0 x 9.3 | 15.8 x 10.2 | 10.2 x 10.2 |
| 10 ct | 15.1 | 18.7 x 12.9 | 13.1 x 13.1 | 16.4 x 11.7 | 19.9 x 12.9 | 12.9 x 12.9 |
Length x width in mm. A round stone shows one number, its diameter.
mm to carat for a round turquoise
If you know the size, this is the weight. Measure across the widest point of the stone, face up.
- 4 mm
- Weight: 0.19 ct
- 5 mm
- Weight: 0.37 ct
- 6 mm
- Weight: 0.63 ct
- 7 mm
- Weight: 1 ct
- 8 mm
- Weight: 1.5 ct
- 9 mm
- Weight: 2.13 ct
- 10 mm
- Weight: 2.92 ct
- 12 mm
- Weight: 5.05 ct
Turquoise against diamond
How wide a round turquoise is next to a round diamond of the same weight.
- 0.5 ct
- Turquoise: 5.6 mm
- Diamond: 5.1 mm
- Difference: +0.4 mm
- 1 ct
- Turquoise: 7.0 mm
- Diamond: 6.5 mm
- Difference: +0.5 mm
- 2 ct
- Turquoise: 8.8 mm
- Diamond: 8.1 mm
- Difference: +0.7 mm
- 3 ct
- Turquoise: 10.1 mm
- Diamond: 9.3 mm
- Difference: +0.8 mm
- 5 ct
- Turquoise: 12.0 mm
- Diamond: 11.0 mm
- Difference: +0.9 mm
Turquoise properties
- Density used in the charts
- Value: 2.76 g/cm3 (range 2.6 to 2.9)
- Hardness (Mohs)
- Value: 5 to 6
- Refractive index
- Value: 1.61 to 1.65
Opaque, usually cut as a cabochon. Soft, so it suits earrings and pendants better than a daily ring.