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hardness
by Detric Miles
Physical Geology
Fall 2013
  

Mohs Scale of Hardness
Lesson Plan
 

The following is a lesson plan to teach 5th grade students about Mohs Scale of Hardness.

 

Friedrich Mohs was a German mineralogist who came up with a way to determine the hardness of rocks and minerals by doing a scratch test. The scale goes from 10 (being the hardest) down to 1 (being the softest). The hardness number is determined by the harder rock or mineral scratching the softer rock or mineral.

 

Mohs Scale of Hardness Lesson Plan

 

Teacher:  Sherry Harris                         Title:  Mohs Scale of Hardness

Subject(s):  Geology                              Grade(s):  5th Grade
Objectives:  The objective of this lesson is to understand the hardness of different minerals and everyday objects as well as where they fit on Mohs Scale of Hardness.

 

Materials Needed

1.    Minerals

·         Talc         

·         Gypsum

·         Calcite

·         Fluorite

·         Apatite

·         Feldspar

·         Quartz

·         Topaz

·         Corundum


 

2.    Everyday Objects

·           Marble

·           Aluminum

·           Copper

·           Tile

·           Acrylic

·           Slate

·           Sea Shell

·           Fingernail

·           Pyrite

3.    Observation Tools

·           Magnifying Glass

·           Worksheet

·           Pencil

Brief Description:  Observe minerals and everyday objects for a few minutes and make note of any evident details. Then scratch minerals with everyday objects and record findings. Complete lesson with a teacher guided review.

 

Lesson:
Step 1:   Vocabulary

Split students up into small groups and have them look up the definitions of each vocabulary word together making sure everyone in the group understands the definitions before they go on to the observations. Approximately 10-15 minutes.

 

Step 2:  Observation

Observe the minerals using three of their five senses and make note of any details they can see, smell, and touch (color, texture, size, shape, etc.) please discuss those details with one another. Make sure you use the magnifying glass to get a good look at each of the minerals. We could add taste, but it's not recommended as you never know what the mineral is or where it's been not to mention the germs we would be passing around so we will discuss this option, but not use it. Approximately 10-15 minutes.

 

Step 3: Scratch Test

Students will take listed materials and scratch them to each of the nine minerals and see where it fits in on Mohs scale of hardness. A diamond will be discussed in class for learning purposes, but we won't actually have one to use. Approximately 15-20 minutes.

 

Step 4: Complete Worksheet

Students will then fill in the information they learned from their observations and scratch test.

 

Step 5: Teacher Guided Review

When all of the students are done we will go over some of the observations and scratch test results. Then collect papers for grading. Approximately 20 minutes.

 

Some of the questions to be asked are as follows:

1.    What colors did you observe?

2.    What did the minerals feel like?

3.    What was the texture like; smooth, rough, soft, sharp, slick, etc.?

4.    Did any of the minerals have a odor to them?

5.    What hardness number did you give each of these objects on Mohs Scale of Hardness?


 

·           Fingernail                           

·           Aluminum                           

·           Copper                                

·           Tile                                       

·           Acrylic                                 

·           Slate                                    

·           Sea Shell                            

·           Marble                                 

·           Pyrite                                   


 

 

We will finish off our discussion with a talk about everyday uses for some of these minerals. Talc is used in talcum powder and makeup. Gypsum is in plaster of Paris and sheetrock. Calcite can be found in limestone, marble, and antacids. Fluorite is in our water and toothpaste as fluoride. Apatite is the same mineral as your teeth. Feldspar is found in granite countertops. Quartz is one of the most common minerals on Earth and is found in sand and glass. Topaz is found in jewelry mainly pendants and earrings.  Corundum is found on sandpaper and in jewelry as rubies and sapphires. Diamonds are found in jewelry and also on sandpaper.

 

Assessment:  Teacher guided review with a question and answer session along with grading the worksheets the students fill out.

 

Standards:

1.    Strand 1 Inquiry Process

1.1. Concept 2 Scientific Testing (Investigating and Modeling)

1.1.1.   PO1 Demonstrate safe behavior and appropriate procedures (e.g., use and care of technology, materials, organisms) in all science inquiry.

1.1.2.   PO5 Record data in an organized and appropriate format (e.g., t-chart, table, list, written log). (See W05-S3C2-01 and  W05-S3C3-01)

2.    Strand 1 Inquiry Process

2.1. Concept 4 Communication

2.1.1.   PO1 Communicate verbally or in writing the results of an inquiry.  (See W05-S3C3-01)

2.1.2.   PO3 Communicate with other groups or individuals to compare the results of a common investigation.

 

 


 

Vocabulary Words

 

Working in your group, look up the definitions of each of these words. Please put the definitions is your own words.

 

1.    Rock                                                                                                                                                                                                                                                                         

2.    Mineral                                                                                                                                                                                                                                                                     

3.    Opaque                                                                                                                                                                                                                                                                                                                                                                                                              

4.    Transparent                                                                                                                                                                                                                                                                                                                                                                                                      

5.    Translucent                                                                                                                                                                                                                                                                                                                                                                                                      

6.    Density                                                                                                                                                                                                                                                                                                                                                                                                               

7.    Hardness                                                                                                                                                                                                                                                                                                                                                                                                           

8.    Color                                                                                                                                                                                                                                                                                                                                                                                                                   

9.    Luster                                                                                                                                                                                                                                                                                                                                                                                                                 

10. Streak                                                                                                                                                                                                                                                                                                                                                                                                                 

Mohs Scale of Hardness Worksheet

 

Please complete this once your observations and scratch testing are done.

 

 

1.    Please describe for me what you observed using your sense of sight?

Corundum                                                                                                                     

Topaz                                                                                                                             

Quartz                                                                                                                             

Feldspar                                                                                                                        

Apatite                                                                                                                            

Fluorite                                                                                                                           

Calcite                                                                                                                            

Gypsum                                                                                                                         

Talc                                                                                                                                 

 

2.    Please describe for me what you observed using your sense of smell?

Corundum                                                                                                                     

Topaz                                                                                                                             

Quartz                                                                                                                             

Feldspar                                                                                                                        

Apatite                                                                                                                            

Fluorite                                                                                                                           

Calcite                                                                                                                            

Gypsum                                                                                                                         

Talc                                                                                                                                 

 

3.    Please describe for me what you observed using your sense of touch?

Corundum                                                                                                                     

Topaz                                                                                                                             

Quartz                                                                                                                             

Feldspar                                                                                                                        

Apatite                                                                                                                            

Fluorite                                                                                                                           

Calcite                                                                                                                            

Gypsum                                                                                                                         

Talc                                                                                                                                 

 

4.    What hardness number would you give each of these objects on Moh's Scale of Hardness?


 

·           Fingernail                           

·           Aluminum                           

·           Copper                                

·           Tile                                       

·           Acrylic                                 

·           Slate                                    

·           Sea Shell                            

·           Marble                                 


 

·           Pyrite                                   


 

 

5.    Why do you think we didn't use a diamond in class for the scratch test?                                                                                                                                                                                                                                                                                                                                                                                                                                

 

6.    What mineral feels soapy?                                                                                                                                                                                                                                 

 

7.    Were there any minerals you could scratch with your fingernail? Why do you think that's possible?                                                                                                                                                                                                                                        

 

8.    Can you see through any of the minerals?                                                                                                                                                                                                    

 

9.    Did any of the minerals leave a mark on the tile?                                                                                                                                                                                                     
 

Mohs Scale of Hardness

 

10

Hardest

Diamond

Description: Faceted Diamonds.jpg

9

Corundum

Description: Corundum.jpg

8

Topaz

Description: Topaz.JPG

7

Quartz

Description: Quartz.jpg

6

Feldspar

Description: Feldspar (orthoclase).jpg

5

Apatite

Description: Apatite.jpg

4

Fluorite

Description: Fluorite.JPG

3

Calcite

Description: Calcite.jpg

2

Gypsum

Description: Gypsum 2.jpg

1

Softest

Talc

Description: Talc.jpg

 

Pictures courtesy of Roger Weller, Geology Instructor, Cochise College

Works Cited

 BIBLIOGRAPHY (2013, November 23). Retrieved from Lesson Plan Source: http://lessonplansource.com/rocks-and-minerals-unit-lesson-4/
Kelley Dunbar, M. B. (2013, November 23). Mohs Hardness Test . Retrieved from GK-12: http://gk-12.osu.edu/Lessons/03-04/Physical%20Science/MohsHardnessTest.pdf

King, D. H. (2013, November 24). Retrieved from Geology: http://geology.com/

Lesson 4: How Can We Tell the Hardness of Rocks? (2013, November 23). Retrieved from Teachers Network: http://teachersnetwork.org/teachnet-lab/ps101/bglasgold/rocks/lesson_4.htm

Mineral Hardness: Mohs Hardness Scale. (2013, November 24). Retrieved from All About Gemstones: http://www.allaboutgemstones.com/mohs_hardness_scale.html

Moh’s Hardness Scale. (2013, November 23). Retrieved from HotChalk’s Lesson Plans Page: http://lessonplanspage.com/sciencemathmusicpeartsslamdrocks-mohshardnessscale12-htm/


Moh's Hardness Scale
. (2013, November 23).
Retrieved from This Planet Really Rocks!: http://library.thinkquest.org/J002289/mohs.html

MOHS' SCALE OF HARDNESS. (2013, November 24). Retrieved from Mineralogical Society of America: http://www.minsocam.org/MSA/collectors_corner/article/mohs.htm

Mohs Scale of Mineral Hardness. (2013, November 24).
Retrieved from American Federation of Mineralogical Societies: http://www.amfed.org/t_mohs.htm

Stevens, E. (2013, November 23). Mohs Scale of Hardmess. Retrieved from Cochise College Geology Home Page: http://skywalker.cochise.edu/wellerr/students/Mohs/project.htm
 

           Weller, R. (2013, November 23). Retrieved from Cochise College Geology:
           http://skywalker.cochise.edu/wellerr/aawellerweb.htm