Could it be marcasite? I am no way deeply knowledgable but this caught my eye and I did a bit of research. Great find. Would love to hear where you found it and a bit more about your hunt.
Hi Jessi
I found it on our farm close to Port Elizabeth ( that is in the Southern coastal parts of South Africa)
Jessi what do you think of the ( i think ) pyrite i found that i also posted
I persoanlly do not see any of the typicall "Green" color assoatced with Libethenite. As for the marcasite aspect.. it would show more of a pyrite or shine, shimer effect to the stone which it doesn't..