Dark Elemental Core

Discription
Dark Elemental Cores lootable from Meteors and Dark Elemental are used in advanced spell's, Spell Tower element selection, summoning and armour. They can also be harvested by farming Darkweed Seeds, as well as nodes containing Darkstone

Quote
"The living heart of darkness. Use to conjure an Dark elemental at a summoning pool"

- In-game description

Get these by harvesting darkstone with a pickaxe