amazing green rock

[Everson]

[SomethingIsFishy]

It might be Epidote. Where did you find it?

[Coco]

Epidote is a green mineral (silicate), with a specific chemical formula. Here there is no crystalline form, so it is geological and not mineralogical. In addition, we can see lighter or coloured areas differently, which excludes a mineral per se.

 

Coco

Edited December 29, 2022 by Coco

[FranzBernhard]

Could be quartzite with some green mica (muscovite var. fuchsite) in it.

Franz Bernhard

[Ludwigia]

There are so many possibilities that you'd need to either get a chemical analysis or show it to an expert at your nearest natural history museum or university department of geology. Most of us here specialize in fossils and have only a rudimentary knowledge of mineralogy, so it's hard to judge something like this based only on just a few photos.