The phenomena are pretty intricate. E.g. in the initial stages, grinding the mirror is a physical process: you use some very hard material to carve the glass into the desired shape.
But when it gets to polishing (smoothing the surface to optical perfection), it's far more complex. The granules of the agent are microscopic, and the process is in that grey area between physics and chemistry. You end up slicing off only a few layers of molecules at each pass.
It goes on and on like this. It's very addictive if you like Physics. :)
It might be possible to handle the size aspect of such multiscale storytelling.[1] Perhaps even down through primary school.
And given a firm grasp of size, and of atoms, it might perhaps be possible to support an integrated and broad modern material science foundation. Maybe... but I'm not being very successful at finding opportunities for exploratory discussion of that. :/
Telescope mirrors might be a nice setting for teaching a lot of interwoven physics and material science stories.
A lot of engineering is like that. I wonder how we might start systematically collecting and organizing such stories, for eventual use in education?