“No!” said Ron. “No, don’t open it! I’m serious!”

“Why not?” asked Harry. “Let’s get rid of the damn thing, it’s been months —”

“I can’t, Harry, I’m serious — you do it —”
“But why?”

“Because that thing’s bad for me!” said Ron, backing away from the locket on the rock. “I can’t handle it! I’m not making excuses, Harry, for what I was like, but it affects me worse than it affected you and Hermione, it made me think stuff — stuff I was thinking anyway, but it made everything worse, I can’t explain it, and then I’d take it off and I’d get my head on straight again, and then I’d have to put the effing thing back on — I can’t do it, Harry!”

He had backed away, the sword dragging at his side, shaking his head.

“You can do it,” said Harry, “you can! Youv’e just got the sword, I know it’s supposed to be you who uses it. Please, just get rid of it, Ron.”

The sound of his name seemed to act like a stimulant. Ron swallowed, then, still breathing hard through his long nose, moved back toward the rock.

“Tell me when,” he croaked.

Harry Potter and the Deathly Hallows – J.K. Rowling