The person who picked up the stone was Tim Brant, a guy in Jon's grade who was a desperate loser with the ladies.
He picked up the stone and looked at it. "Weird, I've never seen a rock like this." He said. "I wish I knew where it came from." The stone flashed, and suddenly he did. he knew it had come, originally, from Peru, and that more recently, Jon had dropped it onto the sidewalk.
"How did I know that?" he asked himself, looking at the stone. He looked around, then whispered. "Um, I wish I knew how I knew that?" he tried, unsure it would work.
And yet, to his surprise, it did, and he suddenly knew that what he held was a wishing stone.
He couldn't help but to grin, thinking of all the things he could do with the stone.