I think they are just iron covered by silver, and so able to rust, etc, but yes, for mist elf it's a problem.

I apologize in advance for my ignorance regarding metallurgy, but if the iron is completely covered in silver then how would it come into contact with oxygen in order to rust? Is silver porous or something? Even allowing that, it's still illogical in the case of smithing and mist elves.

Steel, lead and copper are also made of iron, which allows for a variety of jokes. :)

Defects would explain it. Also, silver itself does tarnish - it's not strictly reacting with oxygen, but it does oxidise (with Sulphur).

IRL, steel is quite definitely made of iron.

Indeed, but for ADOM, they're all exactly the same metal. (Add platinum to that list!)

The first time I noticed this, I arrived at the conclusion the terms refer to the items' color and not the material they're made of.

Also related to issues 1793 and 1804.

Excuse the thread necromancy but:
Why not just put all items made of brass/copper/silver/gold/platinum to a separate category of materials and call them "precious metals"?
That way you don't have to create a separate type of metal for each and assign it 3-5 items and instead have them grouped into a single type with many items.
There are many more inconsistencies in similar vein, like Iron Crown of Havlor actually being made of eternium and so on.
Let iron be iron and not just a generic group to put a number of other materials into.

We're modeling defects in metals now? Iron is probably a DEFAULT VARIABLE. Get real.