Why is there sand in deserts and no dirt? Why isn’t there sand anywhere else?

Question

I figured it was something to do with sand being light enough to be carried by wind, but that wouldn’t explain why the rest of the world lacks sand.

In: 327

Answer 1

Only a small portion of dirt is sand. The bulk of the material is decomposed organic matter, mostly from plants and a bit from animals. In areas with little of either, all that’s left is the sand.