Just so you know, absolutely none of that is true.
https://en.wikipedia.org/wiki/Pyramidion_of_Amenemhat_III
I don't know if the person who posted that is sincere or not, but plenty of people sincerely believe this sort of thing when it is posted on Facebook.
In all fairness, I wasn't there when the archaeologists named it, and I have no idea why they named it that, but yeah it's called a Benben stone, they've been called that for a long time. Yeah it sounds silly, but that's probably the only correct word in their post. ๐คทโโ๏ธ
Yeah, but like I said to someone else, not really... it's like calling the Cleopatra's Needle "the Egyptian obelisk." I mean, yeah, it's an obelisk. But it's not THE obelisk.