Not quite magic, but here are some Obsidian Javelins :
(Fantasy) History –
Obsidian Javelins are only made by the Mute Ones of the human barbarian tribes living around Sunflow Mountain, a dormant volcano deep within Dwarven lands.
The Dwarven King of three hundred years ago tried to wipe out the local human tribes (see the book Dwarven Histories : Wars of the Lichen, most magi or colleges of note have a copy) but found unexpected resistance. The traitor Ringtrue, apprentice of the stonecrafters, delivered the unused Dwarven knowledge of obsidian blade making to the tribal council in personal restitution for his people’s crimes against the tall folk. By the time the armored King’s Hammerers reached the fertile grounds the tribal people occupied at the base of the volcano the tribal warriors were kitted out with Obsidian Javelins which would punch straight through all but the thickest steel plate. The war continued for several years, until a new Dwarven King came to power and terms of a truce were settled. The tribes would maintain their supply of such weapons, but never share the secret with the outside world on pain of a full invasion.
(Actually, the Dwarves have rigged a method via massive floodgates and incredible pumps to force the volcano to become active again. They haven’t done it, but probably will if the tribes violate their end of the bargain.)
The tribes will usually trade such weapons for more industrialized goods at a fair rate, but under no conditions will teach how to make them. Their Makers and their apprentices are universally restricted from speaking to outsiders, ever, about anything, on pain of death (both theirs and the outsiders)
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Obsidian Javelins (Thrown, Near, AP [see below], 5 uses, 2 weight)
The heads of the Javelins are made of lava rock, and are incredibly brittle. They act as regular Javelins, except :
Their frailty makes them a one-use proposition. Using one automatically requires marking a use in their entry of the Gear section.
They have Armor Piercing equal to their thrower’s Strength Mod (a minimum of zero)
The tribes have no use of money but will happily trade for something that makes their lives easier or more enjoyable of at least equal value (of at least ‘ten coin’ per five such javelins)
Well done!