Pyramidion of Amenhotep

 

True pyramids (at least the larger ones), as opposed to step pyramids in Egypt were topped by a special stone called a pyramidion, or sometimes a capstone, which was itself a miniature pyramid. It brought the pyramid structure to a point at the same angle and the same proportions as the main body.

The ancient Egyptian word for the pyramidion, which could also sit atop the apex of an obelisk, was ben-benet, named for the sacred Benben stone kept in the temple of Heliopolis, the oldest center of the sun cult in Egypt. During the Old Kingdom, they were usually made of diorite, granite or a very fine limestone which was then covered in gold or electrum.