Flint glass is obtained from which of the following

Flint glass, also known as lead glass, is primarily characterized by its high refractive index and optical clarity. It is traditionally manufactured from a mixture of sand (silica), red lead (lead tetroxide), and potassium carbonate (potash) [t1][t6]. The lead oxide (red lead) provides the glass with its characteristic density and brilliance, while potassium carbonate acts as a flux to lower the melting point [t6][t7]. While some modern industrial definitions of 'flint glass' refer to clear container glass containing barium or zinc oxides [t4][t9], in the context of classical chemistry and optical glass (used for lenses and prisms), the standard composition involves lead and potassium silicates [t7]. Other options describe different glass types: zinc and barium borosilicate is characteristic of Jena glass [t7], and sodium aluminium borosilicate is typical of Pyrex or heat-resistant borosilicate glass [t2][t8].

Sources

1. [1] https://dn790007.ca.archive.org/0/items/silicasilicates00audluoft/silicasilicates00audluoft.pdf