Ancient Statues will drop Thulecite when mined, but players should avoid mining these when the nightmare cycle reaches high levels, as not to spawn in any shadow creatures. Also, keep in mind the gems these statues have, as they will change in the nightmare cycle until you choose to mine them.
Ornate Chests in Labyrinths will sometimes contain small amounts of Thulecite and Fragments to turn into more Thulecite. Do come prepared for the Dangling Depth Dwellers that live there, as they will often form large groups with the clustered, un-avoidable nests in the maze.
The player may also find some spare Thulecite Walls down in the depths, too. Smashing them will bring in some Fragments, so bring a Hammer with you. Find the closest Ancient Pseudoscience Station to the entrance to the ruins and keep it safe. Feel free to smash any other Stations you find, as they might drop Thulecite as well as other precious gems.