An acquaintance spent five years working in Saudi Arabia. He was amazed to see the Saudi’s importing sand.
When he questioned it he was shown why.
Desert sand that is continually blown by the winds looks like tiny glass beads under a microscope. So smooth that concrete will not properly bind with it.
Beach sand has the nooks and projections that make it the perfect binder for concrete.
The Saudi’s do export some sand for glass making but not nearly as much as they import.
So, the Saudi’s are the ones buying all the sand.