Rosiwal scale

The Rosiwal Scale is a way to measure the hardness of different minerals. Imagine you have a bunch of rocks and you want to know which ones are harder than others.

To use the Rosiwal Scale, you take a special tool called a scratch tester (like a tiny metal stick) and you scratch the surface of the mineral you want to test. If the mineral is soft, the metal stick will scratch it easily and you will see a tiny mark on the surface.

But if the mineral is harder, the metal stick won't scratch it as easily or at all. If the metal stick doesn't scratch the mineral, it means the mineral is harder than the stick and it gets a higher number on the Rosiwal Scale.

Basically, the Rosiwal Scale helps you figure out which minerals are tough and which ones are more fragile. And that can help you learn more about rocks and minerals, and even help you identify them!