Moving on to the Infused metals.
I have a few ideas on this. For version 2, we're going to make the process more complicated but yield more usable bars per gem.
First off, we're going to use Alchemy. This is going to require a few different materials, which I'll probably use for other things as well.
We're going to use Aqua Regia for this. To get there, we'll need a few things:
Vitrol (sulfuric acid) comes from a few places but I'll be using Melanterite, which for convenience will show up as small mineral pockets in coal and lignite deposits.
Alum is a substance gotten from refining Alunite, Schist, Bauxite or Cryolite.
Aqua fortis (Nitric Acid) is made from saltpeter and alum
Aqua Regia is the gotten by combining Vitrol and Aqua Fortis together.
I'm simplifying the actual Alchemy needed to do all of this. Various salts and other things would actually be needed for these processes, but to keep things manageable I'll be going with these basic requirements. Glass vials are going to become very important! Fortunately, between the ability to trade for sand and the increased rock crystal in Civ Forge that won't be too hard.
Aqua Regia will then be used to dissolve the various gems down into an Elixir. You'll get 5 vials worth of Elixir for each Gem.
I still need to come up with names for the various Elixirs.
If you have all four gem types (Frost Crystals, Storm Crystals, Fire Hearts, and Ward Crystals) you can create a Pure Elixir, which will allow for the creation of Elementium. You will only get 5 vials worth, though, so you'll be sacrificing quantity for quality.
Now that we have the Elixir, we'll need somewhere to use it. That's where the Infusion Chamber comes in. The infusion chamber will require stone blocks, a barrel, and gold bars to build. Once it is built you will be able to combine a vial of the appropriate Elixir with Iron Bars to create the various Infused Metals. This process will not require fuel.
So, the end result of all of this is that trading for various minerals is going to be quite important but a small pocket of gems will now give you a much more useful cache of metals to work with.
Thoughts?