Fluorescence
Types and Degrees of Fluorescence in Gems
Fluorescence refers to how effectively a gemstone reflects and refracts light. This guide explains the different fluorescence grades used in gemology to measure a stone's sparkle and fire.
Fluorescence Grades
Exceptional Fluorescence
80 - 90%
The highest level of light performance with exceptional sparkle and fire.
Good fluorescence
60 - 80%
Very good light performance with noticeable sparkle.
Average Fluorescence
40 - 60%
Solid light performance with consistent sparkle across the gemstone. Good cut quality.
Poor Fluorescence
30 - 40%
Limited light performance with minimal sparkle.