Marquise moissanite size chart: mm to carat
By HeyGema™ · Updated
In short
A marquise moissanite labeled 1 carat measures about 10.4 x 5.2 mm, the size of a 1 carat marquise diamond. It weighs about 0.91 carat on a scale, because moissanite is lighter than diamond.
Carat to mm calculator
About 10.7 x 5.4 mm
An estimate for a well-cut stone. A deep or shallow cut faces up smaller or bigger.
Marquise moissanite: size, DEW and true weight
Sizes are length x width in mm of a well-cut marquise at a ratio of 2.00:1. DEW is diamond equivalent weight, the label most stores use. True weight is what the stone weighs.
- 0.5 ct
- Length x width: 8.3 x 4.1 mm
- True weight: 0.46 ct
- Weight in grams: 0.092 g
- 0.75 ct
- Length x width: 9.4 x 4.7 mm
- True weight: 0.69 ct
- Weight in grams: 0.14 g
- 1 ct
- Length x width: 10.4 x 5.2 mm
- True weight: 0.91 ct
- Weight in grams: 0.18 g
- 1.5 ct
- Length x width: 11.9 x 6.0 mm
- True weight: 1.37 ct
- Weight in grams: 0.27 g
- 2 ct
- Length x width: 13.1 x 6.6 mm
- True weight: 1.83 ct
- Weight in grams: 0.37 g
- 3 ct
- Length x width: 15.0 x 7.5 mm
- True weight: 2.74 ct
- Weight in grams: 0.55 g
- 4 ct
- Length x width: 16.5 x 8.3 mm
- True weight: 3.66 ct
- Weight in grams: 0.73 g
- 5 ct
- Length x width: 17.8 x 8.9 mm
- True weight: 4.57 ct
- Weight in grams: 0.91 g
Marquise moissanite by length-to-width ratio
A 1 carat DEW stone at each ratio. The size changes with the ratio, so check the length and the width in the listing.
- 1.80:1
- Length x width: 9.9 x 5.5 mm
- 2.00:1
- Length x width: 10.4 x 5.2 mm
- 2.20:1
- Length x width: 10.9 x 5.0 mm
Questions
A 1 carat DEW marquise moissanite is about 10.4 x 5.2 mm.
A 2 carat DEW marquise moissanite is about 13.1 x 6.6 mm.
No. DEW is the weight of a diamond the same size. A moissanite weighs about 9% less than that.