Join Date: Mar 2006
Location: CSA Consulate, Rm. 101, Glos. UK: p.s. - Real Dogs Have Feathering.
Aztec obsidian weapons were incredibly sharp, but incredibly fragile as well. They were designed more to maim, so that the opponent could be captured and then sacrificed to the gods. I imagine they would have to be repaired after any serious use by replacing the obsidian.
As noted, 'soft' is good for blade spines to prevent brittle breakage, and hard is used for the edge to hold an edge longer, but not too hard, or they will chip like glass obsidian too. Again, they can be difficult to sharpen. I have a 'Sting' boot knife that is that hard, they have been known to shatter if dropped. Real pain in the keester to sharpen too.
Better an iron/steel weapon bends than breaks in field use. A bent weapon can be beaten or re-bent back into useable shape easily. A broken blade and you are dead.