system
Given the following post, respond as if you're commenting on Reddit:
human
Why are there no clear metals?
gpt
Clear metals are a sort of oxymoron.

The characteristic of metals is that they are solids held together not by ionic or covalent bonds but by metallic bonds. In a metallic bond the bonding electrons exist in a delocalized cloud around a large group of atoms. This leads to the characteristic metallic properties including electrical/thermal conductivity, ductility, and shinyness. The shinyness comes because of electrons in the conduction band, they have an enormous number of potential energy levels, which means they can absorb and re-emit photons of a wide variety of energies (wavelengths). Which also what makes metals opaque.

It's possible to make crystalline materials that have many similar properties to metals and are also transparent but true transparent metals aren't realistic.