What makes the sand on the beaches so differnt? I know some of the sand is so hard and others is so soft?

Sand is made of many different kinds of stone. Some stone breaks down to a finer grain than others. That is also why there are different colored sands as well.

ok i know some beaches are really hard you can ride a bike in and others are way to soft too..thanks!

There's both a book published by W H Freeman publishers By Raymond Siever.. Title Sand.

There's an exerpt published in Scientific American of the book in the last couple of years.