Faceting Angle Calculator
Calculate optimal crown and pavilion angles for different gem cuts based on refractive index.
Inputs
Results
Optimal Pavilion Angle
43.37°
Critical Angle40.37°
Pavilion Min42.37°
Pavilion Max46.37°
Crown Angle42°
Cut StyleStandard Brilliant
Table %55%
GirdleMedium (2-4%)
How to Use This Calculator
- Enter the Refractive Index of the gem material (diamond = 2.42, sapphire = 1.77, quartz = 1.55).
- Select the Cut Style: standard brilliant, Portuguese, Barion, or step cut.
- Review the Optimal Pavilion Angle for total internal reflection and the Critical Angle.
- Check the Crown Angle, Table Percentage, and Girdle Thickness recommendations.
- Use the pavilion angle range to set your faceting machine for the first row of pavilion facets.
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