The Barrier Stone is both a research in the Artifice tab and an item. The Barrier Stone, as the name implies, creates a barrier above it that no mob can pass through, although any player can. The block is only approximately 7/8ths blocks tall, and only prevents mobs from passing over itself, including Golems. To fully ward an area, one must completely enclose it in Barrier Stones, or risk allowing mobs, both passive and hostile, in. When the block is activated, runes of different colors are displayed. These runes tell the state that the block is in. Purple means the area is fully protected and no mobs can enter, while blue means the block has been deactivated with a redstone signal and red meaning that mobs are capable of entering. A set of 4 Barrier Stones can be crafted in an Arcane Workbench with 4 Arcane Stone Blocks, and a fire and order Shard, as shown in the picture below, along with 50 Ordo and Ignis Vis.