Glass crown (optical)

See also: Glass crown

The glass crown is a type of glass used in Optique for the manufacture of lenses. Glass crown is produced starting from a alkaline Silicate incorporating an high rate of phosphorous Pentoxyde.

These glasses have a weak Index of refraction, of approximately 1,52, and a Nombre of Abbot raised, higher than 50 (between 50 and 85), they thus have weak a chromatic dispersion.