what is the critical angle of diamond?

Answer 1

2.42 is the index of refraction

the critical angle depends on the medium
between diamond and air the angle is approximately 24.4 degrees

Answer 2

The critical angle is that angle at which total internal reflection occurs and is calculated as tc = sin^-1(n0/nd), where nd is the refractive index of diamond and n0 is the refractive index of the adjacent medium. The refractive index of diamond varies with wavelength and is influenced by impurities. At 589 nm (yellow), the refracive index is approximately 2.417, which yields a critical angle of 24.44 degrees in air. Actually, total internal reflectance applies to the propagating part of the electric field only. An evanescent electric field, which decays exponentially to 1/e over a distance of approximately one wavelength is present at the site of internal reflection. This evanescent electric field may interact with material proximate to the surface and is the basis for a very sensitive infrared spectroscopy method. Diamond is a useful (if somewhat expensive) material for internal reflectance elements due to its strength, thermal conductivity and chemical resistance. -- Optical Physicist

Answer 3

2.42 is the refractive index of diamond and its critical angle is 38 degree.

Answer 4

It's around 2.5. I'm thinking it's 2.45 but I'm too lazy to go look it up in my physics book tonight.