In fairness the pop-sci media never got the memo. They keep calling it "transparent aluminum."

It's interesting to highlight the fact that all metals necessarily look shiny and opaque due to the way their electron configurations -- that "sea of electrons" which is common to all metals -- interact with visible light.

Some metals are transparent in other wavelengths, though. Beryllium is famously transparent to x-rays.

I agree. It's very similar to https://en.wikipedia.org/wiki/Corundum that is transparent unless it has some minor contamination that gives it a color and is call "ruby", "sapphire", ... Nobody call ruby a metal.