Flint glass


Flint glass

Flint glass is optical glass that has relatively high refractive index and low Abbe number. Flint glasses are arbitrarily defined as having an Abbe number of 50 to 55 or less. The currently known flint glasses have refractive indices ranging between 1.45 and 2.00. A concave lens of flint glass is commonly combined with a convex lens of crown glass to produce an achromatic doublet lens because of their compensating optical properties.

With respect to glass, the term "flint" derives from the flint nodules found in the chalk deposits of southeast England that were used as a source of high purity silica by George Ravenscroft, circa 1662, to produce a potash lead glass that was the predecessor to English lead crystal.

Traditionally, flint glasses were lead glasses containing around 4%–60% lead oxide; however, the manufacture and disposal of these glasses are sources of pollution. In many modern flint glasses, the lead can be replaced with other additives such as titanium dioxide and zirconium dioxide without significantly altering the optical properties of the glass.

Flint glass can be fashioned into rhinestones which are used as diamond simulants.

See also

*Crown glass (optics)
*Chromatic aberration
*Cup plate

References

*Kurkjian, Charles R. and Prindle, William R. (1998). Perspectives on the History of Glass Composition. "Journal of the American Ceramic Society", 81 (4), 795-813.


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  • flint-glass — [ flintglas ] n. m. inv. ou flint [ flint ] n. m. • 1764, 1855; angl. flint « silex » et glass « verre » ♦ Opt. Verre à base de plomb, très dispersif, utilisé en optique. ● flint ou flint glass nom masculin ( …   Encyclopédie Universelle

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  • Flint glass — Glass Glass (gl[.a]s), n. [OE. glas, gles, AS. gl[ae]s; akin to D., G., Dan., & Sw. glas, Icel. glas, gler, Dan. glar; cf. AS. gl[ae]r amber, L. glaesum. Cf. {Glare}, n., {Glaze}, v. t.] [1913 Webster] 1. A hard, brittle, translucent, and… …   The Collaborative International Dictionary of English

  • flint-glass — flint ou flint glass (flint ou flint glas ) s. m. Verre en cristal servant avec le crown glass à faire les lentilles achromatiques des microscopes ; il est constitué par 3 atomes de quadrisilicate de plomb et 2 atomes de quadrisilicate de potasse …   Dictionnaire de la Langue Française d'Émile Littré

  • 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… …   The Collaborative International Dictionary of English

  • Flint glass — Flint Flint, n. [AS. flint, akin to Sw. flinta, Dan. flint; cf. OHG. flins flint, G. flinte gun (cf. E. flintlock), perh. akin to Gr. ? brick. Cf. {Plinth}.] 1. (Min.) A massive, somewhat impure variety of quartz, in color usually of a gray to… …   The Collaborative International Dictionary of English

  • flint glass — flint′ glass n. opt an optical glass of high dispersion and a relatively high index of refraction, composed of alkalis, lead oxide, and silica …   From formal English to slang

  • flint glass — n. a hard, bright glass containing lead oxide and having a high index of refraction, used for lenses, crystal, etc …   English World dictionary

  • flint glass — Optics. an optical glass of high dispersion and a relatively high index of refraction, composed of alkalis, lead oxide, and silica, with or without other bases, sometimes used as the diverging lens component of an achromatic lens. [1665 75] * * * …   Universalium

  • flint glass — noun optical glass of high dispersion and high refractive index • Syn: ↑optical flint • Hypernyms: ↑optical glass * * * noun 1. : glass formerly made using calcined flints as a source of silica 2. : heavy brilliant glass that contains lead oxide …   Useful english dictionary