Orpiment is arsenic sulfide. In the past, it's been used as a fly poison and to tip arrowheads. It's pretty toxic. I'm not sure why my brother Brent is worried about me putting the plants I pick outside in his food when I've got so many minerals in my collection which are so deliciously poisonous. Orpiment isn't stable in full sunlight and specimens are usually kept in completely dark drawers. I keep this one in w/ the rest of the collection. If I kept it somewhere else, I couldn't enjoy seeing it daily plus if it outlasts me, it will just end up in a garage sale somewhere anyway.