From the Miocene
Collected from Mcdermitt,Southern Oregon,USA.
This material often called Larsonite,or green Jasper,but more well known as Gary green
it is in fact petrified swamp wood,fossilised 11-14 million years ago,and is a result of dead trees,swamp vegetation and mud,all having been covered with a coating of ash from a volcano, and the silica rich minerals all add to give it a lovely green colouration.
The specimen is polished and measures 109mm x 78mm