Glowy Yellow Crystal
A large pretty piece of pulsing crystal. It's pleasantly warm to the touch.
Fluffikins the fox likes to Barter with these crystals, which he refers to as Ensorcelled Hassium.
They kill you. Slowly, sometimes, or quickly. Depends on the person. But they're full of magic! A magic that's hard to find elsewhere. With proper prep, they can make amazing armors and weapons. I'm not a crafter myself, so I don't know any details. But I do know that lead-lined storage boxes can protect you from the sickness. Really, any storage is better than keeping them in your pocket!