Why does transparent plastic become opaque when it breaks?

Question

My 7yo snapped the clip off of a transparent pink plastic pen. He noticed that at the place where it broke, the transparent pink plastic became opaque white. Why does that happen (instead of it remaining transparent throughout)?

This is best illustrated by the pic I took of the [broken pen](https://imgur.com/S8rasqb).

In: Physics

Answer 1

The break isn’t completely clean. The plastic probably has really tiny tears and cracks caused by the break which adds to the texture and diffuses light.