You are asking for the refractive index of antimony, a metalloid element. However, refractive index is typically defined for transparent materials, like glass or water, where light can pass through and bend.

Antimony is not transparent. It is a solid metal with a metallic luster. Therefore, it doesn't have a refractive index in the conventional sense.

If you are interested in the optical properties of antimony, you might be looking for information on its:

* Reflectance: How much light is reflected from its surface.

* Absorption: How much light is absorbed by the material.

* Other optical constants: These might be useful for understanding how antimony interacts with electromagnetic radiation.

Let me know if you want to explore any of these aspects further!