Chekov's Spell -- This spell has a two-fold effect. The first is to make the target item almost-unnoticeable to anyone not specifically looking for it. The second is that someone who has seen the item will remember it when they encounter a situation that would be perfectly solved by use of said item.
An alloy of iron and iridescent meteoric metal, also known as shadesteel. Weapons forged of this metal cause gangreneous infections almost instantly and sometimes the victims becomes a shambling zombie after death. The material is very vulnerable to fresh water which will cause it to corrode and eventually melt in a period of hours to days.