Any material transparent in 2-14 micron

At https://www.spectral-systems.com/technical-data-sheet/zns-zinc-sulfide/ the image for IR spectrum at https://www.spectral-systems.com/wp-content/uploads/2016/07/2-mm-ZnS-IR-Spectrum.jpg is missing.

I am trying to find ZnS or ZnSe lenses to test an idea. But since it does not have to be durable, any solid low cost material transparent from 2-18 micron would do.