When Akro made that one, they called it a Moss Agate.
Nowadays, many collectors are resistant to using "Moss Agate" for anything but patches. But Akro called them Moss Agates and was very proud of them. One of Akros most expensive marbles.
Some of those resistant collectors will call yours a Ringer.
But Akro didn't make marbles called Ringers. They had a box, with the Ringer name on it, but that's because of the game called Ringer.