Ideas on Realistic Mica Material?

I wouldn’t say it doesn’t look anything like the sample, but I tried to find some more reference and it’s really hard to really get a sense of the material from images online. Iirc mica has a bit of “pearlescence” to it, doesn’t it? I wonder if it’d help to look at the nodes presented here and maybe add a touch of that to your shader?

It also looks like the cutouts have a distinct whiteness in your photo - perhaps add something to enhance the edges, like this: Worn edges material with Cycles (2.74) - how ? - #2 by IkariShinji