Question

What objects refract light?

Answer 1

Any substance that allows any light radiation frequencies to pass through it will refract the light beam.

Explanation:

"Refraction" is the effect that occurs when the light passes between two substances with different refractive indices. It is an interfacial phenomenon and it does not happen within a material itself.
The refracting interfaces may be between similar phases (gas, liquid, solid), or different ones.