IDENTIFYING MINERALS Lesson Plan

Transcription

1 IDENTIFYING MINERALS Lesson Plan TARGET AUDIENCE Third through Sixth grade STANDARDS VA grades 3-5: Scientific investigation, reasoning and logic; Matter. MD grades 3-6: Constructing knowledge; Communicating scientific information; and Materials and processes that shape a planet. DC grade 3-6: Scientific thinking and inquiry; and Earth science.. * See page 4-5 for an in-depth list of standards of learning covered in this program. OVERARCHING GOAL To observe, compare and contrast, and test minerals and use the resulting information to identify them. STUDENT OBJECTIVES 1. Students will observe, compare and contrast a variety of rocks and minerals. 2. Students will test a variety of rocks and minerals for their luster, streak, scratch, color, and magnetism. 3. Students will compare and contrast their activity results with a comparable exhibit in the Geology, Gems, and Minerals Exhibit hall. STUDENT OUTCOMES 1. Students will describe the characteristics of minerals. 2. Students will identify a variety of rocks and minerals based on their luster, streak, scratch, color, and magnetism. MATERIALS, RESOURCES, TIME, SPACE Materials: A variety of rocks and minerals for demonstration and visual reinforcement. A tray of 5 minerals for describing and testing, magnifying glasses; Identifying Minerals/ Discovery Room Activity Sheet #1, Identifying Minerals/ Discovery Room Activity Sheet#2, Mineral Classification Chart, Identifying Minerals/ GGM Exhibit Activity Sheet, Time: 45 minutes in the Discovery Room. Space: Discovery Room; Geology, Gems, and Minerals Exhibit. Denotes helpful suggestions and/or accommodations! 1

2 PROCEDURE Welcome: Scientist Discussion (2 minutes): Teachers and students are welcomed. The lesson begins with the instructor referencing a scientist in the museum who studies the earth (which includes studying minerals): Geologists. Students will practice being Geologists as they explore different minerals and learn how to identify them using two important tools their sense of sight and touch. Brainstorming (Focus on Students Previous Knowledge) (5 minutes): First, students will be asked to think about what they already know about identifying minerals (this will activate prior knowledge and help the students become more comfortable providing thoughts). Students will be asked to think of rocks, gems or minerals they have seen How would they describe them? Students will provide descriptions of the rocks and minerals, describing what they see and feel. Examples of both rocks and minerals will be passed around to help support students in their brainstorming. As students provide descriptions the instructor will strategically place them into 4 groups without headlines. This will prepare them for their next activity. When a large enough list has been created students will be asked what each group has in common; what do all the words describe (this will help with observation, interpretation and prediction skills)? For example, rough, smooth and bumpy all describe Texture. Other groups to be discussed: Hardness, Color and Luster. The instructor will explain that Texture, Color, Luster and Hardness are all physical characteristics scientists look at when identifying minerals. Helpful Suggestion: Remind students to use their senses, eyes and hands, when describing the minerals. Encourage them to reflect on what they see and feel. Remind them that there can often be more than one right answer. For children with reading, auditory disorders and ESL, it may help to review what the words mean after the group brainstorm. You can also draw a picture to visually remind students of the word s meaning. For their first activity, students will work in teams and use their observation skills to examine and describe 5 different minerals, just like in the group brainstorm. First they will describe how the mineral looks and feels. Second, they will chose a characteristic that is unique to each mineral in comparison to the other minerals (E.g. one mineral might be FLAT compared to the other minerals, one might be a unique color). This activity will help students become more comfortable and familiar with observing characteristics, in particular similarities and differences. Centers (Exploration and Discussion in Small Groups) (5 minutes): The students will be divided into five groups. Each group will be provided one tray of 5 different minerals. Each station will be managed by one chaperone/and or volunteer who will record what the student s say in order to enhance the student s flow of thinking. Students will be encouraged to work as a team, talk out loud and that there is often more than one right answer. If stumped, students should refer to the list of characteristics generated during the group brainstorm. 2

3 First, students will describe what they see and feel (Focus on Observation Skills) think about texture, color, hardness and luster. Second, they will chose a characteristic that is unique about the mineral. What stands out in comparison to the other minerals? Helpful Suggestion: Throughout both activities, always ask the students for their ideas first, however, you may need to model effective thinking and/or problem solving skills. For children with ADD, ADHD and visual processing difficulties, the minerals will be numbered and correspond with numbers on the activity worksheet to function as a reference during group discussion as well as help with organization. Reconvene (Modeling for Small Group s Activity 2) (5 minutes): The students will reconvene after completing their first step as scientists. They used their observation skills to describe the minerals. For the next activity students will take their scientist skills one step further. They will return to their groups and conduct a series of tests, which will help them gather more information about their minerals. In order to provide a visual model of thinking for the students, the instructor will briefly model each test: Luster, Streak, Color, Scratch and Magnetism. Additional visuals, information and questioning will be provided when appropriate to reinforce information. There are 5 different tests to complete, so each individual is encouraged to take a turn at conducting a test. When finished, they can look at the answer key. Review their test results and match them to a mineral. If they are uncertain about any of their answers, they can retest this is part of being a scientist! Centers (Exploration and Discussion in Small Groups) (20 minutes): The students return in their groups. The chaperone/ and or volunteer will guide them in conducting each test. Students should also take turns recording in order to help practice documenting in charts. Helpful Suggestion: Remind students that there are many tests to perform, so all members of the group should have the chance to perform a test. It is important to discuss with their classmates, listen to ideas and work as a team. For students with processing difficulties and ESL, review the definitions of the characteristics on Activity Sheet #2 and give examples. When the students are finished conducting the tests, the chaperone / and or volunteer will provide the group a Mineral Key so they can compare their findings with listed characteristics and discover the names of the minerals, which they should then document on their charts. Retest if necessary! Reconvene (Reflective Thinking) (5 minutes): To take the student s thinking one step further and to prepare them for their post lesson activity, the instructor will display a powder and ask the students: Which mineral from today s testing do they think is in the powder? WHY? They should use reasoning based on their testing. Think of color & hardness. (E.g. Talc is soft and white). In other words, they could eliminate the hard minerals and minerals which streak tests weren t 3

4 white. Students will be encouraged to use the information gathered from their tests to determine or make educated guesses regarding minerals in everyday objects. Students will be asked to give themselves a round of applause for being such excellent Geologists today! Closure (Thinking Post Lesson) (2 minutes): Students will be encouraged to visit the Gems and Minerals Hall to examine the ways in which scientists have organized the displays. Their challenge is to find the minerals they identified and find out how people use these minerals in everyday life, as demonstrated through the use of talcum powder in the reflective thinking. The students and teachers will be thanked for coming, and also the chaperones for their assistance. Students will be encouraged to visit again! 4

5 STANDARDS VA grades : a) observations are made g) data is gathered and charted into a table 3.3: Students will understand that objects are made of materials that can be described by their physical properties. 4.1: a) Distinctions are made among observations, conclusions, inferences and predictions. 5.1: a) Minerals are identified using a classification key e) Data are collected and recorded into a table form. h) An understanding of the nature of science is developed and reinforced. 6.1: a) Observations are made that can be used to discriminate similar objects. k) An understanding of the nature of science is developed and reinforced. MD Grades 3-6 Grades 3-5: o Standard 1.A.1.d) Recognize that the results of scientific investigations are seldom exactly the same, and when the differences are large, it is important to try to figure out why. e) Follow directions carefully and keep accurate records of one s work in order to compare data gathered. o Standard 1.C.1.a) Make use of and analyze models, such as tables and graphs to summarize and interpret data. Grade 5: o Standard 2.A.3.a) Observe and classify a collection of minerals based on their physical properties. Grade 6: o Standard 1.A.1.g) Give reasons for the importance of waiting until an investigation has been repeated many times before accepting the results as correct. DC Grades Keep and report records of investigations and observations using a table Discuss the results of investigations and consider the explanations of others Demonstrate the ability to work cooperatively while respecting the ideas of others and communicating one s own conclusions about findings Appropriately use simple tools such as paper clips, magnets and scratch tiles to help solve problems Recognize and describe how results of similar scientific investigations may turn out differently due to inconsistencies in methods, materials, or observations, or the limitations of the tools used Write descriptions of investigations, using observations as support for explanations Identify better reasons for believing something rather than citing comments such as, Everybody knows that, I just know, or Because they say, and discount such reasons when given by others. 5

6 Define a mineral as a naturally occurring, crystalline inorganic solid substance. Recognize that each mineral has its own characteristic properties (e.g., quartz, mica) Describe the physical properties of minerals, including hardness, color, luster, cleavage, and streak, and recognize that one mineral can be distinguished from another by use of a simplified key Recognize and describe how results of similar scientific investigations may turn out differently because of inconsistencies in methods, materials, and observations, or limitations of the precision of the instruments used Identify processes all scientists use to investigate natural phenomena, such as collection of relevant evidence, the use of reasoning, the development and testing of hypotheses, and the use and construction of theory in order to make sense of the evidence Record and organize information in simple tables and graphs, and identify relationships they reveal. 6

7 IDENTIFYING MINERALS Background Information for the Teacher Note: You do not need to share this information with students before the program. Some of it will be discussed in the program or you may use it to enrich post-activities or future activities. Mineral Minerals are naturally occurring materials that make up every rock and pebble in the Earth s crust. Minerals are all formed by natural processes and have a crystalline structure. Gem Gemstones are mineral crystals that are beautifully colored or sparkling and are tough enough to be cut and polished. There are over 3,000 different kinds of minerals, but only about 130 of them are gemstones. Of these, only about 50 are commonly used. The rarest and finest kinds of gemstone are called precious gems; more common kinds are called semiprecious gems. Look of a Mineral Reniform rounded, bubbly shape rather like kidneys. Hematite is reniform. Botryoidal rounded, bubbly shape rather like a bunch of grapes. Acicular very thin, needle-like crystals. Tabular flat crystals. Massive minerals which seem to have no definite shape. Streak A mineral s streak is the color of the powder left when the mineral is scraped across a special unglazed tile. While many minerals vary in color to look at, their streak typically remains the same color. To test for streak locate a porcelain kitchen or bathroom tile. Turn it over and use the unglazed back. Break the rock down into individual minerals if you can. If you use a lump of rock, scratch with the mineral you want to identify. Hardness The ten-point hardness scale, called the Mohs scale after Friedrich Mohs, Professor of Mineralogy, who invented it in 1812, is used as a standard measure of mineral hardness. Mohs Number Mineral Mohs Number Mineral 1 Talc 6 Orthoclase 2 Gypsum 7 Quartz 3 Calcite 8 Topaz 4 Fluorite 9 Corundum 5 Apatite 10 Diamond 7

8 Luster The way the surface of a stone looks when it reflects light. Dull no reflection. Greasy like the surface of margarine or butter, shiny but not as bright as glass. Metallic like the surface of metal, such as steel. Silky no reflection. Vitreous like glass, very shiny. Gravity When comparing two objects, the heavier one has a greater specific gravity. To be accurate with specific gravity you should always compare the weight of the specimen with the weight of an equal volume of water. Water has a specific gravity of 1. Most minerals have a specific gravity of at least 1 (which is why they sink). Most are about 2.5 to 3.0, but some are much higher. Gold, for example, has a specific gravity of See Pellant (1997) for formula for calculating specific gravity. Cleavage Flat flakes breakage in one place (e.g., mica). Long blocks breakage in two planes results in (e.g., feldspar). Cubic chips breakage in three planes at right angles to each other (e.g., halite). Rhombic breakage in several planes at oblique angles to each other (e.g., calcite). Magnetism Platinum, iron ore, magnetite (sometimes called lodestone), and pyrrhotite act as natural magnets. Color The mineral composition results in a range of colors. Three different colored samples may not be different minerals, but simply different colored versions of the same mineral. Fracture Not all minerals cleave along flat planes. Many break unevenly. This is called fracture. Conchoidal fragments are like shells Hackly jagged Splintered Chemical Composition Every mineral is made from a particular combination of chemicals. A few, like gold and sulfur, are pure, or native, elements; most are chemical compounds, made from certain elements bound together. 8

9 List of Minerals and Gems and their characteristics Gem/Mineral Hardness Gravity Cleavage Fracture Luster Chemical Composition Quartz Gems 7 Avg None Uneven to Vitreous Silicon dioxide conchoidal Agate 7 Avg None Conchoidal Vitreous or Silicon dioxide waxy Opal Low None Conchoidal Vitreous or resinous Silicon dioxide w/ water Garnet High None Uneven or conchoidal Vitreous Silicate of aluminum, with iron, calcium Tourmaline Average Indistinct Conchoidal Vitreous Complex silicate of many metals like sodium, magnesium and iron Topaz Over 7 Higher than average Zircon 7.5 Higher than average Perfect Uneven Vitreous Silicate of aluminum, with fluorine and water Poor Uneven to conchoidal Vitreous, adamantine or greasy Jade Under 7 Average Good Splintery Vitreous or greasy Zirconium silicate Silicates of sodium, calcium, aluminum and iron Lapis Lazuli Average Poor Uneven Dull Complex silicate with sodium, calcium, aluminum, chlorine and sulfur Hematite 6.5 High None Conchoidal Metallic to dull Malachite Higher Perfect Uneven to Vitreous or than conchoidal silky average Azurite Higher than average Perfect Conchoidal Dull or vitreous Turquoise 5-6 Average Good Conchoidal Vitreous or dull Iron oxide Carbonate of copper, with water Carbonate of copper, with water A phosphate of copper and aluminum, with water 9

10 Gem/Mineral Hardness Gravity Cleavage Fracture Luster Chemical Composition Gold Very high None Rough Metallic A metallic element Silver Very high None Rough Metallic A metallic element Diamond 10 High Perfect Conchoidal Brilliant The element carbon Beryl 7-8 Average Poor Conchoidal to uneven Vitreous Silicate of beryllium and aluminum Ruby None Conchoidal Vitreous Oxide of Sapphire 9 Higher than average aluminum None Conchoidal Vitreous Oxide of aluminum Glossary acicular Adjective. Very thin, needle-like crystals that a mineral may take. botryoidal Adjective. Round or bubbly shape that a mineral may take. chemical compounds Noun. Minerals that are made from certain elements bound together. cleavage Adjective. The way a mineral breaks. composition Noun. The particular combination of chemicals that make up a mineral. conchoidal Adjective. When the fragments that the mineral breaks up into are shaped like shells. fracture Verb. When a mineral breaks unevenly. gem Noun. Mineral crystals that are beautifully colored or sparkling and are tough enough to be cut and polished. gravity Noun. Heaviness or weight. hackly Adjective. When a mineral fractures, or breaks, in a jagged manner. luster Adjective. The way the surface of a stone looks when it reflects light. magnetism Noun. The properties of attraction possessed by magnets. mineral Noun. Naturally occurring materials with a crystalline structure. Mohs scale Noun. Ten point hardness scale used as a standard measurement of hardness for minerals and developed and named after Friedrich Mohs. precious gem Noun. Rare and fine quality gemstone. pure element Noun. Chemical element consisting of only one stable isotope. rhombic Adjective. A type of cleavage in minerals where breakage occurs in several planes at oblique angles to each other. reniform Adjective. When a mineral has a round and bubbly shape. semiprecious gem Noun. More common forms of gems. streak Adjective. The color the mineral leaves behind when it is scraped across a special type of unglazed tile. tabular Adjective. When a mineral has crystals that have a flat appearance. vitreous Adjective. Very shiny, like glass. 10

11 Resources Suggested Web Sites: Smithsonian National Museum of Natural History The Dynamic Earth U.S. Geological Survey The Learning Web Suggested Books: Pellant, C. (2002). Rocks and Minerals, Smithsonian Handbooks. New York, NY: Dorling Kindersley Publishing. Dietrich, R. V. and Skinner, B. J., (1990). Gems, Granites, and Gravels: Knowing and Using Rocks and Minerals. London, UK: Cambridge University Press. References Cheney, G. A. (1985). Mineral Resources. New York, NY: Franklin Watts. Pellant, C. (1999). Collecting Gems & Minerals. New York, NY: Sterling Publishing Co. 11

12 IDENTIFYING MINERALS Discovery Room Activity Sheet #1 Student Names: Observe the 5 minerals provided in your tray: 1.) Describe what you see and feel. Reflect on the group brainstorm. Think about color, texture, luster, etc. List as many physical properties (characteristics) you can think of. 2.) What physical properties are unique to each mineral? What stands out when you compare it to the other minerals? Mineral Number Physical Properties: What do you see and feel? What physical properties are unique to this mineral?

13 IDENTIFYING MINERALS Geology, Gems & Minerals Hall Activity Sheet Names: Pick one of these minerals, find out where it is found, and if possible, what it is used for. How many uses can you find? Mineral /exhibit location Graphite Diversity Study Gallery, Native Elements Where in the world is it found? Uses Hematite Biotite Diversity, Silicate Family (look under Muscovite) Talc Diversity, Silicate Family Magnetite Diversity Study Gallery, Oxides/Carbonates 13

14 IDENTIFYING MINERALS Post Activity to do in the classroom Reconstructing the Classroom Objectives: Listed in the beginning of the lesson plan Time: 55 minutes Materials: Activity sheets from Museum visit, Important U.S. mineral resources and their uses information from teacher packet and Post activity work sheet. Post Activity Discussion (15 min) Students share their findings from the Geology, Gems, and Minerals hall. Teacher lists the uses for the minerals identified at the Museum. Post Activity Application/Problem Solving (20 min): Hand out a copy of the Important U.S. mineral resources and their uses sheet from the teacher packet. Explain that the students will now investigate their classroom to find out how many different minerals it would take to reconstruct the classroom. Hand out the Identifying Minerals post activity sheet and have the students work in groups to identify the minerals used to make important objects in the room. These objects can be things in the room as well as the room structure and infrastructure (walls, wiring and water supply, for example) Post Activity Discussion (20 min): Members from each group present their findings to the class. Extension: If time allows, students can research where in the world to find the minerals used to reconstruct the classroom and use maps to in their classroom presentation. 14

15 IDENTIFYING MINERALS Post Activity Sheet Names: Your challenge is to find the different minerals that are needed to reconstruct your classroom. Look at the objects in your classroom. What minerals are needed to make them? Mineral Name What does it make? 15

16 IDENTIFYING MINERALS Important U.S. Mineral Resources & Uses MINERAL RESOURCE Aluminum Antimony Arsenic Beryllium Bromine Cadmium Copper Diatomite Gallium Garnet Gold Gypsum Iron Lime Lithium Magnesium Mercury Mica Molybdenum Nickel Potash Silver Titanium Vanadium Zinc USES Used in airplanes, rockets, ships, tractor trailers; wire; firefighter suits Batteries, lead alloys, fire-proofing, ammunition Insecticides, herbicides, copper alloy Copper alloy used in computers, electronic communication equipment, nuclear reactors Gasoline additive, fire extinguishers, manufacturing processes Batteries, pigments, metal plating Wires, electric motors, generators, electric equipment, roofing and plumbing materials, cooking utensils, coins Filters Microwave, solar energy, laser, and electronic equipment Abrasives Used to back up a country s economic wealth ; jewelry; coins Wallboard Steel Cement, fertilizer, chemicals Chemicals, nuclear fuel, batteries, TV tubes Flash bulbs; metal Chlorine, appliances Electronics, paint, electric insulation Steel alloys Aerospace and defense industries (helps to resist corrosion) Fertilizer Used to back up a country s economic wealth; jewelry; coins Aircraft engines, rockets, submarines, paint, ink, and paper Ingredient in steel and titanium alloys used in many aircraft parts Vehicles, radiators, tubing, rubber 16

17 IDENTIFYING MINERALS Discovery Room Activity Sheet #2 Student Names: Conduct the following tests on the minerals in your tray. Place the results in the chart below. When you are finished filling out the chart; compare your results with the mineral key provided. Discover the name of each mineral by matching your results to one of the mineral descriptions. Remember, it is ok to retest that is part of being a scientist! Record the names of each mineral in the chart. Number Luster (metallic or nonmetallic) Streak Color Scratch (harder or softer than a paper clip) Magnetism (yes/no) Name