The stone left in place of Jon's original stone looked almost exactly the same. In visible light it did, anyway.
It worked very similarly to the way Jon's original stone did, but it wasn't nearly as powerful. It could only affect things within the wisher's line of sight, and it couldn't rewrite history. It couldn't create magical effects that continued for more than a few seconds after the wish was spoken; whatever was wished for had to obey natural laws after the initial creation or transformation. This stone had a limited self-awareness and a strong sense of ethics; it would refuse to do anything that was likely to harm a sentient being. It wouldn't even transform the living flesh or minds of sentient beings without their informed consent. It did have one trait that was clearly better than Jon's original stone: It had no restriction on undoing wishes.
