In its composition, a special flint is a pure lead-borate glass, containing aluminum oxides and lanthanum.
The purpose (scope):
A special flint is a new type of glass with a lower relative partial dispersion in the blue part of the
spectrum compared to conventional flints. It is the best material for creating apochromatic optical
systems for correcting the secondary spectrum in the visible region, due to the extremely low value of
the relative partial dispersion.
Produced at JSC " lytkarinsky optical glass plant"