Question: what are refractive index glass?
Answer: Some typical refractive indices for yellow light (wavelength equal to 589 nanometres [10−9 metre]) are the following: air, 1.0003; water, 1.333; crown glass, 1.517; dense flint glass, 1.655; and diamond, 2.417. The variation of refractive index with wavelength is the source of chromatic aberration in lenses.