Classroom Management:

Prior Knowledge:

Guiding Questions:

Learning Objective(s):

Benchmark(s):

SC.4.E.6.2 Mineral Mysteries SC.4.E.6.2: Identify the physical properties of common earth-forming minerals, including hardness, color, luster, cleavage, and streak color, and recognize the role of minerals in the formation of rocks. SC.4.N.1.2: Compare the observations made by different groups using multiple tools and seek reasons to explain the differences across groups. SC.4.N.1.5: Compare the methods and results of investigations done by other classmates. The students will be able to: • Conduct tests to determine hardness and streak color of common minerals. • Identify the color, luster, and cleavage of common minerals. • Recognize that minerals are combined to form rocks and that different combinations form different rocks. Guiding questions are broad questions that the teacher can use to “guide” the student learning process and can be revisited at any point in the lesson. • How do scientists classify unfamiliar mineral samples? • How can you tell the difference between two similar-looking minerals? In Grade 2, students learned that soil is made up of many things, including small particles of rock, and that Earth is made of rocks in many shapes and sizes. In Grade 1, students learn about things that are found on the Earth’s surface.

Where to find mineral samples: In the Scott Foresman Science adoption, every Grade 4 teacher’s kit included a kit of mineral samples. Also, Grade 4 teachers who attended the 2009 Summer Science training received a 4-box set of rock and mineral samples. If neither of these are available at your school, you can order samples from a science supply store. Once you have the samples: You will need to number the all the samples of a single mineral. To do this, use liquid white correction fluid to paint a small white circle on each sample. Then, once it’s dry, use a thin-tipped permanent marker to write the number of the mineral in the white circle. For example, all the quartz will have the number 1 on them, while all calcite samples have a number 2 on them. This is for ease in speaking about the samples, comparing results, and putting the samples away after use. Testing Materials: One of the necessary testing materials is an unglazed ceramic tile. Consider asking the parents of your students if anyone has any leftover tile from kitchens, bathrooms, or floor. Even if they are glazed on one side, the back side is unglazed and is a wonderful test surface. Also, consider asking your local home improvement store if they have any damaged tiles that they would be willing to donate.

Submitted by: Wendy Shelden, Brevard Public Schools Page 1 of 4

Engage:

Materials:

SC.4.E.6.2 Mineral Mysteries For each team of 4 students:  mineral samples (You need 6-12 different minerals—see Classroom Management for how to acquire and number them. You only need one sample per type of mineral, but the testing flows better if each team has their own sample of each mineral.)  hand lens  unglazed ceramic tile (see Classroom Management)  Hardness test materials: nail, metal nail file, penny Show the video, ―Identifying Minerals‖ from Robert Krampf at http://thehappyscientist.com (Brevard Public Schools have a subscription.) In the video, Mr. Krampf goes through all the ways that scientists test minerals, describing the various tests the students will be conducting. Tell students that they are going to be doing the same tests on mineral samples. Students will need a Mineral Testing Chart. They can use the one attached at the end of this lesson or copy it into their science journals. Have them perform the following tests on each sample and record the results on the Mineral Testing Chart.  Color Have the students observe each mineral sample for the dominant color.

Explore:

 Luster—the reflective nature of the mineral Have the students observe each mineral sample for luster, based on the following descriptions:  dull—these minerals have the same shine as dirt…in other words, none!  glassy—these minerals are similar to glass (appears to be able to see through it)  metallic—these minerals are very reflective, like shiny metals  Fracture/Cleavage—how a mineral breaks when under stress Using the hand lens, observe the edges of the mineral sample, where it is broken. Are the broken edges:  a rough, irregular surface? If so, it has the property of fracture.  in a regular, repeating shape that retains the crystal structure? If so, it has the property of cleavage.  Streak Test—the color of the crushed mineral’s powder Take each mineral sample in one hand. While holding the unglazed ceramic tile with the other hand, scratch the sample against the tile. Observe the color of streak that is left on the tile.  Hardness Test—how well a substance will resist scratching by another substance Hold the mineral sample in one hand. Try to scratch it with your fingernail. Did it leave a scratch in the mineral? Post this Hardness Range chart on the board:  If it can be scratched by the fingernail, write ―less than 2.5‖ in the Testing Chart.  If it isn’t scratched by the fingernail, but is scratched by the penny, write ―between 2.5 and 3.5‖.  If it isn’t scratched by the fingernail or penny, but is scratched by the nail, write ―between 3.5 and 4.5‖.  If it isn’t scratched by the fingernail, penny, or nail, but is scratched by the nail file, write ―between 4.5 and 6.5‖.  If it isn’t scratched by any of the items, write ―greater than 6.5‖.

Submitted by: Wendy Shelden, Brevard Public Schools Page 2 of 4

SC.4.E.6.2 Mineral Mysteries 

After they’ve completed the testing, have the students compare their results to the Moh’s Scale of Hardness: 1. Talc (Softest) 6. Feldspar 2. Gypsum 7. Quartz 3. Calcite 8. Topaz 4. Fluorite 9. Corundum (ruby, sapphire) 5. Apatite 10. Diamond (Hardest)

Explain:

Have students work in their team to decide where on the chart their mineral samples may fall. For example, a mineral that has a hardness ―less than 2.5,‖ is softer than calcite 

As a whole group, have the teams share their test results. If there are any discrepancies, have the students describe how they tested the sample. If necessary, have the debating groups re-do the tests. (Addresses SC.4.N.1.2 and SC.4.N.1.5)



On The Happy Scientist website for ―Identifying Minerals,‖ there is a Minerals Identification Chart. Print this out for the students so they can identify some of their samples. It’s not critical that they identify all the samples. What’s important is that they go through the process of testing minerals.

Evaluate:

Elaborate:

Q&D – for teacher to guide learning and whole group discussion.  Were there some minerals that were more difficult to identify? Why? (Some samples may not be pure, therefore the students’ test results may not be the same as the reference sample. Also, our tests aren’t as precise as professional testing labs.)  When might this kind of testing be used? (When a new, unfamiliar sample is found; also, these tests were performed on rocks brought back from the Moon during the Apollo missions.) To fully teach this benchmark, students will need to recognize that all rocks are composed of minerals. Collect some rock samples—particularly rocks that have large particles visible. Have the students observe the rock samples with a hand lens. Do they see anything that looks like the mineral samples they’ve been studying? The following website is a simulation of mineral testing: http://academic.brooklyn.cuny.edu/geology/leveson/core/linksa/mineral_invest_intro.html In this simulation, students virtually test a number of minerals. They will use (virtually) all the tests completed in the EXPLORE section, but they will also complete other tests. Consider opening a ―Rock Museum‖ in your class. Have students bring in their personal collections of rocks and minerals. Students set up their ―displays,‖ then act as museum tour guides as the other students tour the museum. Give the guides an opportunity to tour the museum, too. Diagnostic and/or formative assessments are embedded within the lesson for the purpose of identifying preconceptions and driving instruction so the students have increased opportunities to learn the important ideas related to the topic. Summative Assessment: Give the students some new samples of minerals. Have them conduct a test on the minerals and classify them according to their test. NOTE: Students don’t need to identify the samples, just classify them. For example, a student performs the streak test on the samples, then groups them in the following way: Group 1 has a white streak, Group 2 has a black streak, and Group 3 has a brown streak.

Submitted by: Wendy Shelden, Brevard Public Schools Page 3 of 4

SC.4.E.6.2 Mineral Mysteries

Mineral Testing Chart Mineral Sample

Color

Luster

metallic / dull / glassy

Fracture or Cleavage

Streak Color

1 2 3 4 5 6 7 8 9 10

Submitted by: Wendy Shelden, Brevard Public Schools Page 4 of 4

Hardness Range