i got the refractive index range;
solid Refractive Index
Crown glass 1.5 – 1.62
Diamond 2.417
Flint glass 1.57 – 1.75
Ice 1.31
Plexiglas 1.49
Polystyrene 1.59
Salt 1.52
looks like flint glass is the range which i need;
flint;
a hard grey rock consisting of nearly pure silica (chert), occurring chiefly as nodules in chalk.
Flint glass is optical glass that has relatively high refractive index and low Abbe number (high dispersion). 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.
In the optical glass industry, flint glass is any highly refractive lead-containing glass ( Flint glasses contain 45-65% lead oxide)used to make lenses and prisms. Because it absorbs most ultraviolet light but comparatively little visible light, it is also used for telescope lenses. The light-dispersive power of flint glass can be made twice as high as that of crown glass (of conventional soda-lime composition), and the two complementary types of glass are cemented together to make lenses corrected for chromatic aberration. In the container glass industry, flint glass is any clear glass free of colouring.
with regards