Floating Rock Pets - Science, geography & art!!

We are very lucky to live so close to the ocean – we often go for walks along the coastline and visit our local tide pools searching for animals.

Today my 4yo Daughter found a lot of rocks along the shore – she asked if we could make them into some rock pets, a craft we often do with random rocks she collects.

Little did Miss M know that she had collected a different kind of rock today – Pumice Stone. I thought these would make a FUN addition to our pet rock family – Floating pet rocks!

This ended up turning into a great science experiment – we tested them against normal rocks in a clear jar filled with water. The regular pebbles sank straight to the bottom however the Pumice Stone floated every time.

Discussion points –
Do the rocks look similar?
Miss M “they are the smae size but one is black the other is grey. The grey one has little holes in it…but the black one doesn’t”

How do the rocks feel in your hands?
The grey one is rough and light, the black one is heavy and smooth.

What do you think they grey one floats?
Miss M – because it’s lighter than the black one…and it’s magical!

Why do Pumice Stones Float?
We looked them up on the Internet together to learn why they float and were both surprised to learn they came all the way from a far away volcano…and they had most likely been floating in the ocean for a very long time. See related news article – http://www.sunshinecoastdaily.com.au/news/vast-amounts-of-pumice-washed-up-on-coast-beaches/1831377/

We then watched a few utube clips of active volcanoes and wondered how much Pumice Stone a volcano could make… There was A LOT on our beach today.

As an experiment we added some green & blue food dye into some glass jars filled with water and stuffed some of the Pumice inside – Miss M was laughing at how it kept trying to pop up and escape ;). We left it in this solution for half an hour then placed it onto some paper towel to dry. *the food die didn’t really absorb into the pumice so we didn’t notice a huge change in the colour.

I knew Mikayla wold love making and playing with these in the bath – so I would need to choose the type of glue & paint carefully so as everything didn’t wash off in the bath. I consulted with my hubby and decided to use super glue (not my favourite glue at all) and nail polish to help decorate them! I used some nail polish to paint on a smile and some superglue to add the googley eyes.

***only an adult can use superglue as its extremely dangerous for kids – I would never usually use it but we wanted these to last in the bath and therefore water soluble glue wouldn’t work.