Beryl

Beryl is a rare ore that spawns in the world after Eater of Worlds has been defeated. It can only be mined with a Meteorite Pickaxe or a higher level. When mined, it gives you Beryl Cluster, which can be smelted into a Classified Beryl Bar with 5 (4) Beryl Clusters. It can only be found in the lower cavern level of the world, and only in the underground level below the desert.