Septarian nodule

Okay kiddo, so a septarian nodule is like a rock that can be found underground. It looks like it's made up of different colors and shapes, like a puzzle.

You know how sometimes when you break a cookie it might have special parts inside, like nuts or chocolate chips? Well, the same thing happens with the septarian nodule. When it was forming underground, some parts of it got filled with special things like crystals or minerals.

Then, over time and with the help of the earth's movements and pressure, the rock got harder and the special parts stayed inside. So now, when we find a septarian nodule, we can see all of the interesting and unique things that got caught inside.

Some people even like to cut open the nodule to see what's hidden inside, just like opening up a present!