Ugh, do not make normal steel weapons "magic" for Dark Sun, ye gods the problems that would cause, and I've warned others of it often enough in the past elsewhere!
"
Oh so we find a +1 steel longsword...does that make it a +2 then?"
bad bad bad!!
Inferior materials = penalties not benefits.
Don't screw up the baseline
With 4th ed though, it's easy, just say inferior materials do not get the bonuses to hit you normally get with proficiency with a weapon, or less of the bonus, dead easy!
They are after all
Inferior.
wood -2 attack, stone -1 attack, obsidian varies, as small pieces of obsidian are every bit as good as steel for somethings, better in fact (razor sharp) they just break now and then, larger chunks though break too much so an obsidian shortsword is largest youd likely get without magic/psionics.
See also South American obsidian edged swords..they could slice you to bits.
So, say a shortsword of wood would only give +1 attack, rather than +3?
But it's easy to imagine materials as good as steel (there is already in Dark Sun, agafari wood for example, also drake hide for armour etc). So, psionically tempered obsidian, drake claws etc could stand in for steel.
You need steel on Athas for beasties like the braxat which have damage reduction against everything but metal (which makes sense), and they don't break. You could say stone/obsidian weapons break on a roll of "1", nice and simple.
If you think about it, on Athas, wooden clubs/staves or ones made of ivory; daggers/spears/javelins and handaxes edged with obsidian or flint, and the sling, are the most likely weapons by logic.
Good wood is uncommon and valuable (compared to Earth and the Realms etc)
Longblades require very high tensile strength materials, and obsidian etc has too many flaws so it owuld shatter too often (though psionics or magic could fix that), so long and greatswords would be very rare.
Athasians are ignorant due to lack of chance to learn by books and culture etc, so skills would be kept to secrets in families/clans etc. They not stupid though, quite the opposite, so crafting skills would be damn good, or they'd have all perished!
One clan would know how to psionically temper obsidian, another how to make chitin armour as good as scale mail, and jealously guard their secrets.
