Green natural stone is rare! The most famous and popular natural green granites for countertops are Uba Tuba and Verde Peacock -two Brazilian Granites. These classical green granite countertops make your kitchen area cool!
But if you want some new and exotic green granite countertops, try Gaya Green quartzite, that is much harder than natural granite countertops, meanwhile price is at high end.
Also other natural green stone is highly recommend for special projects, like 5-star hotels St Regis uses it -Verde Ming marble.