Runes In Rings
"That's a black iron shield! That's something that not even we could buy. It's from the southern black iron mine dungeon. They only sell a set amount to us. Only people with experience forging can use it!" The black iron that anyone had seen was nothing close to what came from the south.
The southern cities were few because of the heat and desert environments. But they had a few mountains that broke up the rough terrain. On one of those such mountains, there was the black iron mine. The pore might have been found in other places but the best of the best was found in that single mine dungeon.
What was even more shocking was that it was a heavily guarded secret. Many people had tried to get permission to go there. To learn to forge it, and mine it. But no one had managed to get the privilege from another city. Even the citizens that lived in the south had a very slim chance.