PokéBase - Pokémon Q&A
4 votes
Good question I've wondered that myself.

1 Answer

8 votes
Best answer

Well, According to what I learned in Science Class, Sand is a naturally occurring granular material composed of finely divided rock and mineral particles. The composition of sand is highly variable, depending on the local rock sources and conditions. When combined by Wind, it forms a Sandstorm which is basically Particles of Rock. That is why Sandstorm is a Rock type and not Ground..