That's a great question! When rock is broken down but the minerals that make it up don't change, it's called physical weathering.

Here are some examples of physical weathering:

* Frost Wedging: Water seeps into cracks in rocks, freezes, expands, and puts pressure on the rock, eventually breaking it apart.

* Abrasion: Rocks are rubbed against each other by wind, water, or ice, causing them to wear down.

* Exfoliation: Layers of rock peel away due to pressure changes, often from the removal of overlying rocks.

The key takeaway is that physical weathering changes the size and shape of rocks without altering their chemical composition.