Calibrated Size Charts for Gemstones to be set in Standard Jewelry Mountings
The weights given are for diamonds cut to ideal proportions. Colored stones are usually cut with greater volume than diamonds; therefore, they will weigh more than the chart sizes. The density of the material will also affect the weight. For example a 6.5 mm round diamond, sapphire and opal, all cut in the same proportions will all have different weights. The diamond (with a specific gravity of 3.52,) will weigh 1 carat. A sapphire (specific gravity 4,) will weigh 1.14 carats. The opal (specific gravity 2.15) will only weigh .61 carats. There are subtle variations to this list. For example, some list a .25 carat diamond as measuring 4.1 mm. The point is not to take these figures too literally, but to use them as a starting point for estimating weights.
Oval Cut
Calibrated Size Chart for Standard Jewelry Mountings (approximate weights)
Size in mm Weight in carat
|
|
5x3 |
6x4 |
7x5 |
8x6 |
9x7 |
10x8 |
11x9 |
12x10 |
14x12 |
Alexandrite |
.30 |
.51 |
.80 |
1.45 |
2.00 |
3.60 |
4.25 |
6.00 |
8.90 |
Amethyst |
.23 |
.45 |
.85 |
1.25 |
1.75 |
2.40 |
3.20 |
4.50 |
6.50 |
Aquamarine |
.20 |
.40 |
.75 |
1.10 |
1.75 |
2.25 |
3.00 |
4.50 |
6.75 |
Citrine |
.23 |
.45 |
.85 |
1.25 |
1.75 |
2.40 |
3.25 |
4.20 |
5.20 |
Diamond |
.25 |
.50 |
.75 |
1.40 |
2.00 |
3.00 |
4.00 |
5.00 |
8.00 |
Emerald |
.25 |
.52 |
.85 |
1.26 |
1.90 |
2.60 |
3.75 |
5.00 |
7.50 |
Pyrope Garnet |
.25 |
.55 |
1.00 |
1.40 |
2.10 |
2.80 |
3.75 |
5.00 |
7.00 |
Iolite |
.21 |
.40 |
.63 |
1.02 |
- |
- |
- |
- |
- |
Opal |
.16 |
.28 |
.47 |
.78 |
1.10 |
1.65 |
2.15 |
3.00 |
4.00 |
Peridot |
.28 |
.50 |
.95 |
1.35 |
2.00 |
2.50 |
3.50 |
4.00 |
6.00 |
Ruby |
.35 |
.60 |
1.06 |
1.55 |
2.20 |
3.15 |
3.80 |
6.00 |
7.25 |
Sapphire |
.35 |
.60 |
1.00 |
1.55 |
2.20 |
3.15 |
3.80 |
6.00 |
7.25 |
Tanzanite |
.20 |
.48 |
.89 |
1.35 |
- |
- |
- |
- |
- |
Topaz |
.28 |
.57 |
1.10 |
1.60 |
2.50 |
3.50 |
4.50 |
6.00 |
8.80 |
Tourmaline |
.25 |
.50 |
.90 |
1.18 |
2.30 |
2.90 |
3.50 |
5.25 |
6.80 |
Tsavorite |
.28 |
.52 |
.75 |
- |
- |
- |
- |
- |
- |
Zircon |
.40 |
.75 |
1.45 |
2.00 |
2.85 |
4.00 |
5.60 |
7.50 |
8.20 |
Round Cut
Calibrated Size Chart for Standard Jewelry Mountings (approximate weights)
Size in mm Weight in carat
|
|
2 |
3 |
4 |
5 |
6 |
6.5 |
7 |
8 |
10 |
Alexandrite |
.04 |
.12 |
.35 |
.63 |
1.30 |
1.86 |
2.15 |
2.90 |
5.20 |
Amethyst |
.04 |
.10 |
.20 |
.40 |
.70 |
1.10 |
1.30 |
1.80 |
3.30 |
Aquamarine |
.04 |
.10 |
.25 |
.45 |
.75 |
1.31 |
1.60 |
2.40 |
3.50 |
Citrine |
.04 |
.10 |
.20 |
.40 |
.70 |
1.10 |
1.30 |
1.80 |
3.30 |
Diamond |
.03 |
.10 |
.23 |
.47 |
.80 |
1.00 |
1.25 |
1.90 |
3.50 |
Emerald |
.04 |
.12 |
.27 |
.48 |
.80 |
1.26 |
1.70 |
2.50 |
6.10 |
Pyrope Garnet |
.05 |
.13 |
.30 |
.60 |
1.00 |
1.40 |
1.60 |
2.50 |
5.75 |
Opal |
.02 |
.09 |
.16 |
.34 |
.57 |
.75 |
.83 |
1.30 |
2.00 |
Peridot |
.05 |
.12 |
.26 |
.50 |
.85 |
1.11 |
1.25 |
2.00 |
5.25 |
Ruby |
.05 |
.15 |
.34 |
.65 |
1.05 |
1.41 |
1.60 |
2.25 |
4.50 |
Sapphire |
.05 |
.15 |
.34 |
.65 |
1.05 |
1.41 |
1.60 |
2.25 |
4.50 |
Topaz |
.04 |
.11 |
.30 |
.56 |
1.00 |
1.36 |
1.55 |
2.50 |
5.75 |
Tourmaline |
.04 |
.12 |
.24 |
.45 |
.75 |
1.28 |
1.55 |
2.00 |
3.00 |
Zircon |
.06 |
.17 |
.36 |
.69 |
1.25 |
1.58 |
1.75 |
2.60 |
5.00 |
Pear Cut
Calibrated Size Chart for Standard Jewelry Mountings (approximate weights)
Size in mm Weight in carat
|
|
5x3 |
6x4 |
7x5 |
8x6 |
9x6 |
10x7 |
12x8 |
14x9 |
|
Alexandrite |
.30 |
.50 |
.85 |
1.10 |
2.10 |
3.60 |
6.60 |
8.80 |
|
Amethyst |
.20 |
.35 |
.65 |
.85 |
1.25 |
1.70 |
4.00 |
5.00 |
|
Aquamarine |
.20 |
.35 |
.65 |
.90 |
1.30 |
1.85 |
4.20 |
5.60 |
|
Citrine |
.20 |
.35 |
.65 |
.85 |
1.30 |
1.70 |
4.00 |
5.00 |
|
Diamond |
.25 |
.50 |
.75 |
1.00 |
1.50 |
2.00 |
3.50 |
5.00 |
|
Emerald |
.25 |
.45 |
.70 |
1.05 |
1.70 |
2.60 |
4.15 |
6.10 |
|
Pyrope Garnet |
.25 |
.40 |
1.00 |
1.15 |
1.30 |
1.80 |
3.50 |
5.80 |
|
Opal |
.13 |
.22 |
.35 |
.50 |
.70 |
1.03 |
1.40 |
2.45 |
|
Peridot |
.25 |
.45 |
.70 |
.80 |
1.10 |
1.40 |
3.40 |
4.75 |
|
Ruby |
.30 |
.50 |
.75 |
1.00 |
1.85 |
2.50 |
4.75 |
7.90 |
|
Sapphire |
.30 |
.50 |
.75 |
1.00 |
1.85 |
2.50 |
4.75 |
7.90 |
|
Topaz |
.25 |
.50 |
1.00 |
1.10 |
2.00 |
3.50 |
6.50 |
8.50 |
|
Tourmaline |
.35 |
.45 |
.60 |
.90 |
1.10 |
1.40 |
2.80 |
6.75 |
|
Zircon |
.30 |
.70 |
1.00 |
1.30 |
2.60 |
4.00 |
5.25 |
7.50 |
|
Octagon / Emerald Cut
Calibrated Size Chart for Standard Jewelry Mountings (approximate weights)
Size in mm Weight in carat
|
|
5x3 |
6x4 |
7x5 |
8x6 |
9x7 |
10x8 |
11x9 |
12x10 |
14x12 |
Alexandrite |
.40 |
.70 |
1.30 |
2.60 |
3.60 |
4.20 |
6.00 |
8.50 |
9.90 |
Amethyst |
.35 |
.55 |
1.10 |
1.60 |
2.25 |
2.90 |
4.20 |
5.60 |
7.25 |
Aquamarine |
.25 |
.50 |
.80 |
1.40 |
2.00 |
3.00 |
4.30 |
4.75 |
7.75 |
Citrine |
.35 |
.55 |
1.00 |
1.60 |
2.25 |
2.90 |
4.20 |
5.60 |
7.25 |
Diamond |
.25 |
.50 |
1.00 |
1.50 |
3.00 |
4.00 |
5.00 |
7.80 |
8.80 |
Emerald |
.30 |
.60 |
.90 |
1.80 |
2.31 |
3.15 |
4.50 |
5.25 |
5.80 |
Pyrope Garnet |
.40 |
.80 |
1.20 |
1.70 |
2.50 |
3.50 |
4.30 |
6.35 |
9.00 |
Peridot |
.35 |
.60 |
1.00 |
1.70 |
2.25 |
3.80 |
5.25 |
6.25 |
8.80 |
Ruby |
.55 |
.75 |
1.15 |
1.60 |
2.30 |
2.75 |
4.00 |
6.25 |
9.00 |
Sapphire |
.55 |
.75 |
1.15 |
1.75 |
2.30 |
2.75 |
4.00 |
6.25 |
9.00 |
Topaz |
.40 |
.65 |
1.25 |
2.40 |
3.40 |
4.00 |
5.75 |
8.00 |
9.50 |
Tourmaline |
.30 |
.60 |
1.60 |
2.15 |
2.80 |
3.60 |
4.30 |
5.20 |
8.50 |
Zircon |
.60 |
.85 |
1.70 |
2.35 |
3.90 |
450 |
6.20 |
7.01 |
8.95 |
Marquise Cut
Calibrated Size Chart for Standard Jewelry Mountings (approximate weights)
Size in mm Weight in carat
|
|
4x2 |
5x3 |
6x3 |
7x3.5 |
8x4 |
10x5 |
12x6 |
14x7 |
|
Alexandrite |
.07 |
.20 |
.30 |
.50 |
.70 |
1.25 |
2.10 |
3.50 |
|
Amethyst |
.10 |
.15 |
.20 |
.34 |
.48 |
.90 |
1.59 |
2.45 |
|
Aquamarine |
.08 |
.14 |
.20 |
.25 |
.50 |
.80 |
1.50 |
2.75 |
|
Citrine |
.10 |
.15 |
.20 |
.35 |
.50 |
.90 |
1.59 |
2.45 |
|
Diamond |
.12 |
.18 |
.25 |
.37 |
.50 |
1.00 |
2.00 |
3.00 |
|
Emerald |
.09 |
.19 |
.30 |
.45 |
.60 |
1.40 |
1.80 |
2.80 |
|
Pyrope Garnet |
.09 |
.16 |
.25 |
.42 |
.60 |
1.20 |
2.00 |
2.85 |
|
Opal |
.09 |
.13 |
.17 |
.27 |
.37 |
.59 |
1.00 |
1.25 |
|
Peridot |
.10 |
.17 |
.25 |
.37 |
.50 |
1.00 |
2.00 |
2.55 |
|
Ruby |
.13 |
.24 |
.35 |
.55 |
.75 |
1.15 |
2.20 |
3.00 |
|
Sapphire |
.13 |
.24 |
.35 |
.55 |
.75 |
1.15 |
2.20 |
3.00 |
|
Topaz |
.07 |
.17 |
.30 |
.50 |
.70 |
1.20 |
2.00 |
3.40 |
|
Tourmaline |
.10 |
.20 |
.30 |
.45 |
.60 |
.85 |
1.55 |
2.20 |
|
Zircon |
.13 |
.23 |
.33 |
.55 |
.75 |
1.25 |
1.95 |
3.00 |
|