A Mana Block is a block that has been turned into something you cannot see. It is the cleanest host for a circle: nothing to look at, nothing to walk around, nothing to break by accident.
What it does
- Invisible. You see the circle on it, not the block.
- Walk through it. Players, pets and ordinary creatures pass straight through.
- Hostile mobs cannot. Hostile mobs and angry neutral mobs are stopped by a Mana Block, and one that would slip across is put back where it was. A tamed pet is never blocked.
- Arrows and other projectiles hit it as if it were solid.
- Shields against effects. Explosions, splash potions and lingering clouds do not reach a creature that has a Mana Block between it and where the blast or bottle went off. Evoker fangs are blocked the same way.
- Indestructible. You cannot mine it.
- Items catch on it. An item dropped or thrown onto a circle on its top or bottom face rests on it instead of falling through.
A Mana Block that carries a Redstone Mana I circle (see Redstone) gives off a redstone signal. It is the only block that can take that circle.
Making one
Sneak and right-click a block with a Mana Gem. The block becomes a Mana Block, and you pay the mana, from your pool and the gems you carry. The default price is 10,000 mana, and the server can change it with mana_block_conversion_cost. If you cannot afford it, the game tells you what it would cost and what you have.
Some blocks cannot be converted: air, a block that is already a Mana Block, a block that has an inventory or other block data (a chest, a furnace), and anything unbreakable such as bedrock. The block you convert is used up, and it does not come back.
Circles on a Mana Block
A block can carry a circle on each of its faces, so a Mana Block can be a whole machine in a single invisible cube. For example, a Smelt circle on the top and a Craft circle underneath.
Removing one
Sneak and right-click it with a Mana Gem again. It disappears in a puff of smoke, every circle on it goes with it, and it drops as a Mana Block item. Place that item and it is an invisible Mana Block again, with no mana to pay.
An alchemist villager at master level also sells Mana Blocks.
Other uses
A Mana Block item is also an ingredient. It is how a Bag of Holding gains columns (see Bags), and it goes into the CAD.