-- Can You Melt Obsidian and Cast a Sword? So I'm sure most of you already knew this, but I hadn't put it together for some reason, but Obsidian isn't a metal, it's a glass. I knew it wasn't a metal but I never took the extra step. THe reason I bring this up as it is common in the fantasy genre to have obsidian be one of the materials a sword can be made of. Then a separate category for glass. Do you use obsidian as a material for weapons? I know that obsidian is known for how precise an edge you can get (at atom thick!), and with magic anything is possible . It's more likely that obsidian would be used in tools. Although I believe native peoples of the Mexico region of north America used jagged pieces of obsidian wedged into a club as a weapon so there is precedent.
It would really depend on the kind of weapon you wanted to use it for. You mentioned the Macuahuitl, which is almost a wooden broadsword, edged with shards of obsidian. It was apparently an effective weapon, but the small blades broke easily so had to be replaced. Still, it was strong enough to take off a man or horse's head so the stories go! Obsidian knives for precise slashing? I could see it. Arrowheads? Definitely, although they'd likely be a "one use" deal depending on if they impacted on wood, bone, or other armor. Spearheads would probably work too, but also be likely to chip and break. I don't think it would work for a sword or larger blade. It seems to work better as fairly small, but very sharp blades (mostly focused on slashing or piercing instead of thrusting). At least not without using magic, of course.
A lot of Native American tribes around Yellowstone, I remember reading, used obsidian for arrow and spearpoints, knives, sewing, scraping hide and surgical instruments and were famous for trading it all over, there was a very extensive network. There's even a few surgeons who used obsidian bladed scalpels today, because the cut is cleaner than steel at the microscopic level which means less tissue damage and better healing. It's just not widespread because it's too easy to cut yourself while using it, and because the blade is fragile.
Obsidian weapons are a thing in Real Life. Macuahuitl - Wikipedia So yes, in a fantasy world where magic can reinforce the obsidian and do other things, why not?
In fantasy and video games, I'm not sure it matters much unless you're going for total realism. Does it even need to be mentioned that gold makes for a poor everything except a few aspects of high-tech and luxury? That doesn't stop authors and scriptwriters making gold armor the absolute top tier, gold swords endgame material that one-shots whatever it touches, and golden weapons of war like solid-gold jets and solid-gold tanks being A1.
*gasp* GOLD armor?! it must be something else. Something mystical that just *looks* gold I get what your saying though: Because author and because magic.
