Obelisks were built throughout ancient Egyptian history, but they became more common during the New Kingdom. The top of an obelisk is pyramid shaped and is called pyramidion, referring to the uppermost piece or capstone of an Egyptian obelisk.
For Becky’s April Squares with the subject top, here are some obelisk tops.
One of the two Luxor obelisks, that originally stood on either side of the entrance to the temple. Both are made from yellow granite and were erected by Pharaoh Ramesses II.
The 2nd of the Luxor obelisks, now at the Place de la Concorde in Paris. It was given to France from Mohammed Ali Pasha, ruler of Ottoman Egypt, in 1833. In 1836, it was placed in its current location. Its pyramidion was missing (believed stolen in 6th century BCE) so the French government added a gold leaf cap.
This obelisk is at the large temple complex Karnak, where there originally were six obelisks. Only two remain. This one was constructed by Pharaoh Thutmose I.
This is what remains of one of the obelisks of Pharaoh Hatshepsut – she had two constructed at Karnak. One still stands. This one is interesting because you can see the top in detail; its pyramidion is still at least partially intact.
Wanderlust & Wonderment 
Quite extraordinary what they created, I would love to see these tops in person