Cycles Crystal Shader

Description:

I don't know if this is useful for anyone, but this is a crystal shader. It uses the refractive index of the mineral quartz, and an attempt at mimicking birefringence (note the refraction around the base is blurry). I used the technique here to get the blurry refractions. It also does a simulated dispersion by having slightly different indices of refraction in red, blue, and green shaders that are then added together. Note that aside from the blurred refraction it looks pretty much like glass; it's said that clear crystal is only distinguishable from glass by a trained eye. Therefore it's probably not worth the effort and render time to use this vs. glass in your scenes, but it's the details that matter. ;)