Monday, 14 October 2013

Rocks and the Mohs scale

We are continuing our science lesson on rocks and minerals.  I am using various resources for our science this year.  I had MarioFan read the Magic School bus book (rocky road trip) and complete this free lapbook.  Whereas Firedrake worked on a lapbook from Hands of a Child which is found here. She also completed a unit study from simply schooling.  We are also continuing to use Real Science 4 kids as our basic spine but I am supplementing quite a bit.

My kids have always accumulated a large collection of rock and we brought a few favorite rocks  back from the UK with us that they couldn't part with.  Currently the kids are assembling their own rock collection from with in the USA as we travel.  It is easy to find igneous and sedimentary rocks, but metaphoric rocks are proving to be a bit harder but we will continue to look while we are in New Mexico .  Before heading out on holiday we learned about the MOHS scale and determining the hardness of rocks.
I found this kit at a local gift shop and brought it home there are several different kinds that can be found on Amazon

Daddy once again helped us with this assignment as he is  a geology major

We used various ways to determine the rocks hardness, fingernail, nail, and streak test

Kids were a little disappointed to see that 80% of the rocks leave a white streak, the only ones we had that didn't were coal.

Since this area fascinated the kids we splurge a little and bought several rock kits that gave 15 samples of each type of rocks.  I was impressed the the size of the samples...This one is of Igneous rocks and the kids were excited to finally have a real pumice stone (more on that further down)

Metamorphic rocks

sedimentary rocks

The kids couldn't wait to try the pumice stone in water

they were so excited to see it float

and tried to sink it many times
By examining each set of rocks we were able to see the minerals and the organization of the minerals that we had read about in our studies.


  1. This is a very interesting article. I am a new home school mom/teacher and I would love to do a study of rocks with my daughter. I just do not know where to start. Any suggestions?

  2. How fun! My son is studying rocks and minerals right now. My dad is also a geologist and a retired teacher, so I put him in charge of my son's science this year--even though we're on opposite sides of the ocean! He mailed us some specimens and has emailed us some power points he made. We've done some of these tests with minerals, and right now we're on igneous rocks. I would love to take my kids rock-hunting with my dad next time we're in American.

  3. How great that your husband is so involved with this activity. I love all the rock kits you've collected.

  4. That's weird that all of your rocks streaked white! I wish I could remember what set we used, but when I did this with Noctis (6 years ago-ish), we had several that streaked different colors (and a couple that streaked down the street, hardy, har, har!). I think it might have been sulfur that streaked yellow???? And we had a rust colored one... It'd be cool if there was a rock that streaked blue!!! Not sure if there is such a thing. We had a very hard time classifying rocks by the criteria. We had numbered rocks and we were supposed to figure out which rock each was, based on a chart we had. I think we had the hardest part in determining the hardness of the rocks???? Well, anyway, it was a bit of a bust for us. It might have been a K12 Earth Science curriculum lab....

  5. Wow, I am learning a lot about rocks. I have a good friend that is a rock collector and she has some awesome ones. You will need to come out west and enjoy all of the rocks that are found here. I love to learn about this great earth that we live upon.