Facet & Critical AnglesLapidary Guild

Calculate the critical angle and recommended pavilion/crown faceting angles based on refractive index to maximize brilliance.

Workshop Parameters
Critical Brilliance Angles
Critical Angle34.6°
Pavilion Mains37.8°
Crown Mains32.3°

Optical Analysis:

Pavilion facets are the mirror backings of your stone. Cutting them below the critical threshold of 34.6° causes complete optical light leakage (windowing), showing the raw skin or setting below.

Refractive and density indexes are values based on gemology standards. Work under correct lighting to avoid angle deviations.

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