Collecting iron powder on the beach

I am a physics and math teacher at a secondary school. I bought a few of your disc magnets 15 x 8 mm for demonstrations about magnetism in the school lab. The students liked that very much.

This summer I tried to collect pure iron to have a stockpile of iron powder for physics experiments in the next school year.

Collecting iron powder on the beach

Collecting iron is actually very easy: The beach of Ostia near Rome has very dark sand due to its high iron content (pure iron powder is black).

I put the magnets into a plastic bag and moved the bag back and forth directly above the sand. The iron deposited itself right away on the outside of the bag in the form of black powder.

Huge collection success

I realized quickly that you can fill a whole glass of iron powder with little effort and lots of fun. You can just use your fingers to remove the iron powder and put it in the glass. It would be almost impossible without a plastic bag.

After a few trials, I made a video with the necessary explanations as well as hints for application possibilities. Especially exciting: It is actually possible to detect the shape of the magnetic field when approaching the sand with the magnets.

This experiment is suitable for primary and secondary schools, if you combine the demonstration with an in-depth theory about the magnetic field.