Word Study
flint glass
CIDE DICTIONARY
flint glass,
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. [1913 Webster]
" The concave or diverging half on an achromatic lens is usually made of flint glass." [1913 Webster]
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