Testing rocks for hardness is an activity that engages children and can either be completed for fun or for challenge and learning. We had a rock testing kit but this can easily be done at home with the free printable PDF. A rock sample kit or just a bunch of found rocks could work. First, we washed our rocks. That was fun and the younger children can be a great “help” for this part of the experiment.

Testing Rocks for Hardness, Acidity, and Magnetism

There are some prediction sorting pages which we printed and had ready, as well as the items with which to scratch. We did not use the fingernail test, but that is one option which could be considered.


The free printable may be downloaded from our free eMember area. Select the free radio button to make the priced options disappear.

Sorting for whether rocks are harder or softer can be done by guessing or predicting.

Testing Rocks for Hardness, Acidity, and Magnetism

Before the vinegar test, predictions might be made about which rocks would fizz or not (how acidic the rocks are).


Are the rocks magnetic or not? A fun test if at least one of the rocks has magnetic properties.

testing rocks

Testing rocks for magnetic properties will require a small piece of iron. Magnetite is magnetic.


We prepared to conduct the copper scratch test. Our kit had a newer penny, but it is wise to find one minted prior to 1982 so that there is actually some copper to use.


Testing rocks with vinegar is so fun it was hard to stop at just one drop.


At first, we were actually guessing with guesses informed by the few tests performed. As the session continues, the process of elimination is used to more correctly place rocks on the chart in the free printable.


There is a blank chart for people who are using rocks found outdoors, also.


We worked hard and reconsidered the which rock specimens were which.


Near the end, we were more confident of our rock and name matching.


Testing Rocks and Recording the Results

This is the testing recording page. More than one may be printed, depending on how many rocks you have. Consult rock books and the internet for more information to help identify rock hardness.


Summer is a fun time for children who enjoy rocks and seem to find them wherever they are, especially on family trips. Rocks make nice educational and inexpensive souvenirs for children to enjoy.

Thank you for reading, Carolyn


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