Extracting Metals from Ore

It's hard to see how magically extracted metal wouldn't be like modern metal. Medieval metal is full of bits of slag, which weakens it. You wouldn't need to fold and hammer it over and over (which is meant to equally spread out the slag so that it doesn't stick in a lump and cause cracks.)

There's an example here of what classically made iron looks like:
youtube.com/watch?v=H47nY2h ... &index=118

Basically my point is: if you are using magic to filter out impurities, your metal's going to be really pure, by medieval standards.

So...Not natural, per medieval standards?

Starting about 9:50, with some lead discussion.

The opposite. Natural, but closer to a state of perfection. Impurities or not says nothing about natural or not. If it did you would have a an absolutely insane nightmare problem of categorisation for various metals when produced by various means, as while the common norm was impure metal, there were plenty enough highend crafters who had various means for getting rid of those impurities to a greater or lesser extent. Then there´s also the issue of how many crafters came up with their own variations for using(and causing) impurities to change the properties of the metal. Nightmare issue is by then not even the beginning if you try to call it "unnatural per medieval standards".

Anyone can do it relatively easily. Oh wow, metal can exist in a solid AND liquid state. Just like quicksilver...

So your argument is that fire is unnatural then... :unamused:

Or any temperature that is warm enough that quicksilver stays liquid is unnatural.

That should work, although it may be a better idea to make the spell so that it is the stone that liquidises away from the metal(no metal getting stuck inside the stone), and then have a second spell that liquifies the pieces of metal so that it can be made into bars or some similarly useful shape for either further working or transportation. The second spell could also be used to make perfectly mixed alloys. Might want a third spell used in between that separates and sorts all metals by type.