Perfect! Sand particles never dissolve in water. Even if you stir the water a lot, you can still see the individual sand particles.
If you add one material to another, and they don't form a uniform mixture and the added particles are visible to the naked eye, the mixture is called a suspension. That is, in a suspension, the added particles do not dissolve. You can see them individually (like the sand particles in water).

Remember, homogeneous means uniform. Suspensions are not uniform mixtures. They are thus called heterogeneous, which is the opposite of homogeneous.
What happens if you take that mixture of sand in the beaker and leave it undisturbed for a long time?
  • The sand mixes better
  • The sand starts to float on top of the water
  • The sand settles down at the bottom of the beaker