Corrosive AmmunitionConsumable 7
Source Pathfinder Advanced Player's Guide
Price 70 gp
Weight negligible
Activate 
Interact
This peculiar ammunition is coated in yellow dust that leaves a stain on anything it touches. When activated corrosive ammunition hits a target, it dissolves across the target's armor. The armor takes 1d8 Persistent Acid Damage that ignores the armor's Hardness; if the target isn't wearing armor, it takes the acid damage instead. This damage occurs at the end of the target's turns.
The creature can end this effect by spending an Interact action to wipe off the corrosive dust, and otherwise the effect ends once the armor becomes broken.
Traits
Anything that doesn't list another rarity trait (uncommon, rare, or unique) automatically has the common trait. This rarity indicates that an ability, item, or spell is available to all players who meet the prerequisites for it. A creature of this rarity is generally known and can be summoned with the appropriate summon spell.
ConsumableAn item with this trait can be used only once. Unless stated otherwise, it's destroyed after activation. Consumable items include alchemical items and magical consumables such as scrolls and talismans. When a character creates consumable items, they can make them in batches of four.
EvocationEffects and magic items with this trait are associated with the evocation school of magic, typically involving energy and elemental forces.
MagicalSomething with the magical trait is imbued with magical energies not tied to a specific tradition of magic. A magical item radiates a magic aura infused with its dominant school of magic. Some items or effects are closely tied to a particular tradition of magic. In these cases, the item has the arcane, divine, occult, or primal trait instead of the magical trait. Any of these traits indicate that the item is magical.