Disjunction

The next magic item you touch becomes a mundane item for the duration as if it were affected by an Antimagic Field. A Potion has a 50% chance of becoming permanently nonmagical. If the item is carried or wielded by an unwilling creature, you must succeed on a melee spell attack against the creature to touch the item. You must be able to see the item. The spell has no effect against Legendary magic items and Artifacts, nor can it be used to reproduce the effects of a Dispel Magic spell.

Using a Higher-Level Spell Slot. If you cast this spell using a 9th level slot, the disjunction becomes permanent if you concentrate for the entire duration. 

Realmslore

A rare subspecies of rust monsters creates this disjunction effect when their antennae touch a magic metal object. The item corrodes like other nonmagical metal objects when subsequently hit by the rust monster but is not destroyed when the penalty drops to -5.  The item gradually reverts back to its magical, undamaged form after being free of the rust monster's touch for at least 1 minute. 

Adapted from the AD&D 1st edition spell of the same name