Mohs' scale of hardness (non-statutory)
I can learn more about the hardness of rocks from the work of important scientists.
- Year 3
Mohs' scale of hardness (non-statutory)
I can learn more about the hardness of rocks from the work of important scientists.
Lesson details
Key learning points
- A geologist is a type of scientist that studies what the Earth is made of. They help us to understand more about rocks.
- Scientists from the past, today and in the future help us to learn more about the properties and uses of rocks.
- The results from a scientific investigation can be compared to other investigations that have already been carried out.
Keywords
Rock - Rock is a solid material that occurs naturally in Earth.
Geologist - A geologist is someone who studies what the Earth is made of.
Hardness - Hardness is the quality of being difficult to bend, cut or break.
Mineral - A mineral occurs naturally and can be dug out of the ground.
Scale - A scale is a set of numbers or amounts, used to measure or compare the level of something.
Common misconception
Children may use a range of observational methods to assess hardness, e.g. “heaviness” of the object, and if it breaks on impact (test for brittleness), neither of which are a test for hardness.
Be aware of using the correct vocabulary around testing for hardness. Explain that hardness is the ability to withstand pressure.
Equipment
See additional resources.
Content guidance
- Risk assessment required - equipment
- Exploration of objects
Supervision
Adult supervision required
Licence
Prior knowledge starter quiz
6 Questions
Q1.The physical properties of a material are things we can or measure.
Q2.Which of these are physical properties of materials?
Q3.Which of these are types of rock?
Q4.If you scratched a rock with a nail you would be testing for ...
Q5.Which of these rocks do you think was used to make this statue?




