Thaumcraft 3 Wiki

The Crucible is the Thaumaturge's tool used to create many of the items he or she researched in the Thaumonomicon. It can be used either to directly craft items out of the Crucible, or to provide the required essentia to a Thaumaturge

Crafting the crucible[]

The Crucible is made by right-clicking a Cauldron with any Magic Wand.

Use of the Crucible[]

Setting up the Crucible[]

To set up the Crucible you need to first fill it with water by right clicking it with a bucket of water. Then, you need to put a fire source (lava, or light a fire) beneath it (most players use netherrack because the fire never goes out.). Wait for the water in the Crucible to start boiling (Yes, it will bubble!) and then you can throw stuff into the Crucible to break down the item. The aspects of the items will be added to the Crucible as essentia.

You can then do four things once essentia are added to the crucible:

  1. Use a recipe from the Thaumonomicon (like creating Thaumium) to create or transmute items.
  2. Dumping the essentia into an Alembic so you may bottle them.
  3. Dumping the essentia into the local Aura to add flux. (Sneak + Right-Click)
  4. Or use the aspects in a nearby Infusion Altar.

Note: Standing in or on top of a boiling crucible will do approximately one heart of damage per second, and will add up to four corpus essentia to the crucible before killing the player. 

Note: If you equip the Goggles of Revealing and look at the crucible, you can see exactly what aspects are inside of it. This is also the same of the Arcane Alembics and the Warded Jars.

Crafting from crucible[]

To craft something out of a crucible (using a known recipe from the Thaumonomicon) you will have to set up the crucible first in the usual manner.

The Thaumonomicon indicates for each craft, what are the necessary aspects and in how many you need. For example: Thaumium requires eight Metallum and four Praecantatio. To gather these essentia you need to drop item in the crucible. They will be broken down into their essentia in as many unit as indicated on the popup for this item (hold shift while hovering the item to see the popup). As an example, an iron ingot is compose of eight Metallum (and other essentia) and Greatwood Log of one Praecantatio. If you throw one iron ingot and four Greatwood Log, you will reach the necessary needs to craft one Thaumium. You can do this by right clicking the crucible with your wand. The Thaumium ingot will be created in the crucible.

It is possible to create batch of such items just by throwing as many essentia as needed to create the number of item you want (example, two iron ingots and eight Greatwood Log to create two Thaumium). Be advise that due to the number of vis required to craft recipe, it is possible to overpass the capacity of one's Wand, even the Wand of the Thaumaturge. The crucible has an animation that shows it completely filled and about to spill over once you reach a certain level of essentia.

Crafting from an Infusion Altar[]

Some recipe of the Thaumonomicon requires the use of an Infusion Altar. These recipes will also require a certain amount of essentia to perform the craft. They can be gathered either from nearby Warded Jars or Crucible.

When the thaumaturge wants to use the Crucible, he or she can proceed with the usual method presented in the previous section. Instead of right-clicking the crucible with a Magic Wand, the player that has put the necessary essentia into the crucible can come back to the Infusion Altar to perform the craft. When getting the item, the crucible will empty in the same manner has it would have done if right-clicked with a Magic Wand.

Note that essentia cannot be taken out of the Alembics set around the Crucible. Please also be aware that only one crucible can be the source of essentia for an Infusion Altar.

Additional tools for the crucible[]

A crucible can be upgraded with a maximum of four tools, one for each side. You can either add Arcane Bellows or Alembic.

Arcane Bellows are used to speed up the boiling of the water. Alembics are use to collect essentia that are left over when performing crafting. Note that one Alembic can only receive a single essentia and up to 16 units of it, so it is common to see more than one for a crucible.

Thaumcraft 4[]

In Thaumcraft 4, crafting a crucible is the same as in Thaumcraft 3. However, its use is a little different.

First you have to put water and a heat source under it and wait for it to boil. Second, put the required aspects from different items by throwing them in it. Last (which is where the process changes), throw an item called a "catalyst" into the crucible. If performed correctly, with the exact amount of aspects and the correct catalyst for that recipe, the desired item will be formed

However, unlike in the TC3, when excess aspects are also included in the water, those aspects will not be used to create the item. If too much essentia is left and not used, it will become flux in the form of either gas or purple goo.

Thaumonomicon Entry[]

The crucible is an important tool for any thaumaturge. It allows him to render physical objects into their component Essentia and recombine in again as he wishes.

The crucible needs to be placed over a source of constant heat and filled with water. Once the water starts boiling you simply throw any item you wish to break down into the crucible and they will be broken down into the component Essentia. You can then use a wand on the crucible and if you got the ratio and amount of essentia right it might be able to craft something.

Any leftover Essentia is simply spilled into the local aura where it forms Flux. If you sneak while clicking with a wand, you will not attempt to craft something and directly spill the Essentia into the aura. This may seem counterproductive... for now.

If you are planning on experimenting with the crucible it is a good idea to keep scribing tools and paper handy in case you discover something.

A crucible filled with water, with two Alembics attached (and a fire beneath)

A crucible with water in it and a fire beneath it


Amount of aspects in a crucible is represented by signed 4 byte variable so it is possible to set it to negative amount by causing overflow (32768 of single aspect will make -32768). Impact on flux after releasing this is unknown.

When there are too much essentia in a Crucible, it will appear to have the water ready to be spilled out of it. Usually, Magic Wands will not have the potential to empty the crucible and the player might have to destroy it.