Elementary School Science

Input:
What is the most important content in this lesson?
To reach this lesson’s objective, students need to understand:

• How minerals are identified.

• Friedrich Mohs Scale of Mineral Hardness.

• The five ways to identify minerals.

• What a scratch test is and why a scratch test is performed.

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How will the learning of this content be facilitated?

• The teacher will begin class by playing the game “Fact or Fake?” to review the information presented on minerals. On the board, draw two columns. Label one column “Fact” and the other column “Fake”. On a desk in front, have a pile of cards. On each card there will either be a real fact about minerals or one that is made up.  Pick up each card and read what is on it. Ask the students to identify if what you read was a fact or if it was made up. Have a student come up to the board and place the card in the correct column. The students will engage in this activity for about 10 minutes.

• Fact or Fake Answers:

  • Minerals are the building blocks of rocks. FACT

  • Minerals are not found in nature. FAKE

  • Oxygen is the main component of minerals. FACT

  • Coal is made up of tiny clear crystals. FAKE

  • Minerals are not manmade. FACT

  • Minerals are made up of dirt. FAKE

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• Next, the teacher will begin presenting the information on Mohs Scale of Mineral Hardness. If it is possible, project each page of the teacher’s copy of the “Rocks & Minerals” Science Journal worksheet onto the board using a projector or put into a PowerPoint document and project.  The teacher’s copy of the journal has certain words/phrases that are bolded red and highlighted. It is important the teacher explain to the students those words/phrases are to be highlighted in their (students) journal. For this lesson, the teacher should review these pages:

• 23: How We Identify Minerals

• 24: Mohs Scale of Mineral Hardness (Background Information)

• 25: Mohs Scale of Mineral Hardness

• Provide This Additional Information:

  • Friedrich Mohs was born on January 29, 1773 in Gernrode, Germany. In school, he studied chemistry, mathematics, and physics. He went to a mining academy in Freiberg, Germany where he was influenced by one of his professors to study mineralogy. In 1801, he moved to Austria and got a job as a mineral curator (someone who cares for a collection). The collection’s owner, J.F. van der Null, was a banker. He wanted to the known minerals organized and the unknown minerals identified. During his time as a curator, Mohs discovered that some of the minerals were hard and some were soft. He observed the way they scratched and created a scale of minerals from softest to hardest. This scale, Mohs Scale of Mineral Hardness, is still used today.

(Source: http://www.kidsloverocks.com/html/friedrich_mohs.html)

• Different items are used to scratch the mineral to test its hardness. When doing a scratch test, you must know the hardness of the tool. If the mineral scratches after using a tool, you know that the mineral’s hardness is less than the hardness of the tool.

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(Source: http://www.eduplace.com/marketing/expsci/pdf/166022_rockserosionweathering/act_166022.pdf)

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• After the information has been presented, the students will perform the scratch test experiment. The teacher should instruct the students to break into their science groups.

**See pages 6 and 7 in the “Rocks & Minerals Experiment Booklet” for the experiment outline**

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Closure

• After the activity is over, the students should reconvene and the teacher should discuss the class.

• Next, the teacher will explain that they are going to do a quick assessment on the lesson. They will answer the questions “What is a scratch test and why do people perform them?”