Bloodborne Wiki

Cursed Odd Arcane Damp Blood Gem is a Cursed Odd Blood Gem in Bloodborne.

In-Game Description

A blood gem that fortifies weapons and adds various properties. Blood gems are especially rare blood stones that grow on coldblood.
Blood gems are kneaded into weapons using workshop tools, but only when of matching shape.
Circular blood gems are normally used to fortify firearms.