When Jesus met Simon son of Jona, he gave him a new name--Cephas. "Cephas" (Aramaic--kefa) is the equivalent of "Peter." The name means "stone." According to Hugh Nibley, kefa is an Aramaic word that refers to a green crystal used for divination. In other words, kefa doesn't just mean "stone" but more precisely it means "seer stone."
The Joseph Smith Translation of John 1:42 is more interesting now, isn't it?
"And [Andrew] brought [Peter] to Jesus, and When Jesus beheld him, he said, Thou art Simon the son of Jona: thou shalt be called Cephas, which is, by interpretation, a seer, or a stone..."
So, two questions:
Is Hugh Nibley right about kefa?
If so, how do you explain Joseph Smith's uncanny ability to get these things right?