What are these?

[Earth]

Although I know these rocks aren't silver they have chips throughout of silver-like substance that shines like a mirror. Wish the photo showed all the silver-like chips...back and front...large pieces of the silver substance....

 

[fishnpinball]

I would guess the sliver is mica. Is it very thin almost transparent sheets? probably a mica schist.

 

[Eu_citzen]

Silvery stuff is Mica (var. muscovite).

 

[smokeythecat]

Agree on mica.