Exactly 2012 stones....I was originally planning this sphere to be a trans-dimensional teleportation device--my ticket out of here for 12/21/2012. Well, it turns out my stone stacking abilities were not equal to the task of building such a device out of stone. Luckily, the zombies did not happen! Anyhoot, silly questions deserve silly answers...or maybe I'm serious? the sphere itself has a radius of 26" and weighs just about 2 tons. thank you