In a fantasy setting I'm working on for an RPG, I was trying to determine what properties I could use to determine how well metals resist magic and how readily they absorb enchantments based on something measurable in the real world. Then it hit me, conductivity.
The rule: More conductive metals would be able to soak up more magic before being saturated, but would also be more vulnerable to magic damage. Less conductive metals would resist magic damage, but could not hold as powerful enchantments.
Going off a world that has the equivalent of ~14th century metallurgy and blacksmithing techniques, which metals would be favorable for magic resistant armor? And which metals would make for the best enchanted weapons and armor?
Keep in mind, they still need to be able to be light enough and durable enough to function as armor and weapons (otherwise I think gold and silver might win in the enchanted category.)
Clarification: The conductivity rule is only for metals. I'm going to work out a different measure for non-metals.