One of the quests requires an Eternal Pillar to be in one's inventory; however, at this time, neither the Eternal Pillar or the Eternal Portal frame can be crafted and/or mined.

Don't they appear naturally in the end? It says in the guide for dummies

Sorry for the late response - They do appear naturally, but the quest requires one in your inventory, not to just encounter one. I'll check this out again and update to see if it's fixed.

You'd have to break it and have it in inventory to complete the quest - this was my intention. Is it not possible?