According to Ezpan's description, that place must be the Colima region, with its continuous mountain ranges and complex terrain, as well as the fickle Tekos Tribe. The black blade should be an oxidized iron sword; considering the tribe's metallurgy level, an iron sword indeed wouldn't be much sharper than bronze weapons. And given the local mining capabilities, they could only pick up scattered pieces of iron ore from the surface, hence forging just a single weapon.
The iron mines of Colima are deeply buried beneath the ground, with shallow deposits dozens of meters down, and even deeper ones at hundreds of meters. For the Alliance, these sporadic pieces of iron ore are merely a drop in the bucket. However, their existence is significant, as they help pinpoint the locations of shallow iron deposits, so that the Alliance can then invest significant manpower and resources to excavate...