petros mostly means small stone, from a marble to a comparatively small stone compared to a big stone
But, Petra is ALWAYS a BIG stone, a LARGE stone, never a small stone
And what people need to do is go back and search the Old Testament and see how many times ROCK is used to describe GOD, not men.
MEN are never called a ROCK, NEVER called a rock that men are to trust.
Only GOD is referred to as a ROCK in the Old Testament
Thanks, Race, for the explanation. Mxxx