Monday, 24 November 2014

Rocks and Mineral Scratch Testing and Mohs Scale

November 24th
Today is science we completed Rocks and Mineral scratch testing.  We talked about Mohs hardness scale; and then we completed the scratch testing on our samples to try and figure out how hard each one was. Each group was given a collection of rocks and minerals and some scratch testing tools including:  a penny, a nail, paper clip, nail file and a magnifying glass.  They recorded their results in their notebooks.

This is Mohs hardness scale.  Students started by trying to scratch their sample with their finger nail. If their finger nail made a scratch mark then we knew that the sample was softer than 2.5.  We classified this sample as very soft.   If it did not make a mark we knew that the sample had a hardness greater than 2.5 so we moved to the next test.  Next they scratched the sample with a penny.  If the penny did not make a scratch mark they moved on to the next test, scratching with a nail.  Students completed these tests for 8 samples and recorded their results in their notebooks.

I am so proud of how engaged and excited the students were today!  They appeared to really enjoy this experiment. 

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