I suppose I came on too strong there. I just hate the general idea in games that descriptions differ but it's all the same as far as the rules go. It was a big problem I had with 4e. I'd much rather spells worked differently too, but at some point you have to accept some abstraction for playability (which is where something like hit points comes in, for example). In this case, if you're going to use a fantasy material like orichalcum, I'd much rather it matter beyond a description.
I guess I draw a distinction between "descriptions," as in what is
done, and "origins," as in where it
comes from. A flametongue weapon always works as a flametongue weapon, you can figure out how that cashes out.
Fireball works as it does in part because that's the structure that "throw a LOT of fire" at someone takes. Etc. But the
origin of that power can be different. Like how you can get a hard sword blade by fancy-schmancy folded nippon steel, or aircraft aluminum, or quenched titanium, or... They're all metal blades with a sharp edge. What differences exist will rarely become relevant because they're beneath the level of detail the game measures. We don't force players to sharpen their blades and weapon breakage rules are rare to nonexistent, 5e removed nearly all weapon properties (other than finesse) so there's no meaningful differences to be had there, etc.
For me, as long as the material reasonably justifies powering a fire-based enchantment, I don't see any value in making 7+ different "it's a sword that gets fiery attacks" based on all the different possible sources for a fire enchantment. The essence of flame is there, it just needs to be strong enough to power the standard enchantment. The
description is consistent because that's what it physically, practically does.
Or, if you prefer a simpler analogy: Your computer doesn't care if it's powered by a river, a solar panel, a bunch of fissioned atoms, burned methane, burned coal, or giant metal windmills. I see the magic--the description--as being equivalent to the computer, not the generators.