Most of them, yes. Except for the granite used in the Grand Gallery and Kings Chamber. But most of the stone used was limestone quarried from the site.
China has pyramds: http://www.philipcoppens.com/china_pyr.html http://www.bibliotecapleyades.net/piramides/esp_piramides_china_3.htm
Our current head of Housing and Urban Development thinks the Egyptian pyramids were grain storage buildings (based on information in the Old Testament of the Christian Bible). So maybe we will see some American pyramids for future generations to marvel at.
It's an old Seventh Day Adventist belief. It's actually pretty interesting if you are into history and mythology. The pyramids got associated with the God of grain, which got associated with Joseph and his legend. The pyramids became the grain silos. Not that there's much room in them, which was established fairly quickly. But once a myth gets started, it's hard to get rid of.
A neighbour built a pyramid across the road. It was excellent. Timber frame clad in corrugated iron. Three levels. Plenty of exposed beams very trendy. Ground had multiple work rooms, first just living and top one large bedroom. It was burnt down in the bush fires which was odd because it seemed most resistant to fire. I have often thought to build one on my back ridge where the view is of the river. But that probably will not happen. Alex
Oh yes. Bad enough with this stuff hanging around. Ancient Aliens and Diggers just helps add more manure on the bonfire
Just dig into Egyptian pyramids a little more . John Anthony West should help . And he does not agree with ancient alien thinking .