It can be crafted in your Crafting Menu (default key "q") after the according crafting recipe has been unlocked by finding a rather rare Recipe Book in an Iron Treasure Chest on the Lava layer underground (ever since R22) or in a Diamond Treasure Chest on the Corruption layer, or even more rarely as a loot or pet-harvest from a Thing, a Silver Keepa or a Golden Keepa.
The block can be rotated by pressing and holding R and moving the mouse while holding the left mouse button.
To craft 8 (blocks of) Blue Mosaic Tile Walls, you'll need:
- 1 Blue Pigment made of Blue Flowers from Elderwood trees in a Processor or found in Obsidian Treasure Chests
- 4 (blocks of) Adobe Bricks, made from Mud in a Forge
- 2 Iron Rods made of Iron Bars in a Processor
- 2 (blocks of) Siltstone from the Stalactite layer underground, mined with at least an Obsidian Mining Cell or better.