Aura Node (Thaumcraft 4)

The Aura Node is a transparent block added by Thaumcraft 4. Nodes generate naturally in the world and are virtually invisible to the naked eye—in order to see them clearly, the player must have either a Thaumometer held in their hand or Goggles of Revealing (or equivalent) worn. Each node will have a randomly generated set of aspects, at least one of which is a primal aspect. Nodes can be tapped by holding down the right mouse button while holding a wand to harness vis from them through their primal aspects.

Brightness
Over time, nodes will recharge their aspects back to their capped levels. The rate at which it does so is determined by its brightness.

Fading nodes, given enough time, will disappear completely from the world. Punching them is suggested in order for them to yield Ethereal Essence.

Types
Aside from the standard node, there are a few different types that have their own characteristics:
 * Sinister: Creates an Eerie biome around it. Spawns Angry Zombies and Furious Zombies when light levels are low enough.
 * Tainted: Creates a Tainted Lands biome around it.
 * Pure: Creates a Magical Forest biome around it. Can be used to keep Tainted Lands at bay.
 * Hungry: Absorbs everything except the sturdiest blocks (i.e., Obsidian) into it and turning items into the aspects that they're comprised of. Entities will be absorbed and take damage. CAUTION: Players are strongly recommended not to approach unless they have some method of capturing it or a means of escape; any deaths in the hungry node's vicinity will absorb all the player's items.

Energized Nodes
Once "Harnessing Vis" in the Thaumonomicon has been researched, the player may be able to energize a node by using a Node Stabilizer and Node Transducer placed below and above the node respectively. While the Stabilizer will use the node's own energy to power itself, the Transducer requires a redstone signal in order for it to be activated. When the Transducer activates it will take the node roughly half a minute before transforming into an energized node which will emit centivis. Once this is done all compound aspects will break down into their primal aspects and wands will no longer be able to harness the node directly.