It is worth noting that breaking a Crystal Core that has been placed will not return a whole core only the Nether Star and Shards used in it's construction, not even an implement with the Silk Touch enchantment will prevent this. Additionally some of the shards will change from their original types to Dull Shards.
Once activated, the Crystal Core will locate the nearest node within a 24 block area and begin pulling it towards the crystal. Note that the larger the size of the node, the longer moving time it will have.
NOTE: It is possible to draw a node further than 24 blocks, but it requires the Wand of Dislocation.
By building the totem setup close to a node, and 'linking' the core to the node, you can then pick up the core using 'right-click' with the Wand of Dislocation. This will preserve the linked node id, so when you re-place the core where you want the node to go, it will continue to pull it.
It is important to note, however, that to re-place the node with the Wand of Dislocation, you will need a block either side of where the Crystal Core is supposed to be, and place it by right clicking the side of either of these blocks. You can then destroy them, so you can complete the structure.
Crystal Cores can also be used to destroy dark nodes. To do this, first create a Pure Node that is more powerful than the Dark Node, then using the Crystal Core, pull the Dark Node towards the Pure Node, and the two nodes will merge, creating a very powerful Pure Node.
When crafting the Crystal Core, remember that you will first need the Wand of the Thaumaturge (or Wand of the Tinkerer).
Aspects Required: Mutatio (8), Vacuos (8), Alienis (8), Praecantatio (8); 50 Vis.