Flint" glass` (?). (Chem.) A soft, heavy,
brilliant glass, consisting essentially of a silicate of lead and
potassium. It is used for tableware, and for optical instruments, as
prisms, its density giving a high degree of dispersive power; -- so
called, because formerly the silica was obtained from pulverized
flints. Called also crystal glass. Cf.
Glass.
☞ The concave or diverging half on an achromatic lens is
usually made of flint glass.