Uh, for concrete the granularity and composition is VERY important. In fact it's one of the most important parameters you can tweak in a concrete mix.

To the point that weird stuff like this happens quite frequently:

https://www.quora.com/Is-it-true-that-Saudi-Arabia-imports-s...

My local DIY store here in the UK carries some 8 different types of sand, all for different purposes.

Actually it matters quite a bit. That's why countries which are literally filled with desert sand import river/sea sand for their construction. Finding a way to make desert sand usable for construction concrete would be significant.