188.8.131.52 Rocks & Minerals
Recognize that rocks may be uniform or made of mixtures of different minerals.
Describe and classify minerals based on their physical properties.
For example: Streak, luster, hardness, reaction to vinegar.
MN Standard in Lay Terms
Rocks are natural materials (not man-made). Rocks are made of minerals and can be classified according to their mineral composition. Minerals can be identified by their physical characteristics such as hardness or streak.
- The concepts of rocks and minerals are based on the beginning understandings of the rock cycle. At this point, students should begin to understand that waves, wind, water, and ice shape the earth's surface and produce the distinctive earth structures that we see. Students should understand that some processes, such as erosion, can occur rapidly; others occur over time. For instance, many of the features of the earth's surface can be traced to glacial movement many years ago. American Association for the Advancement of Science. (1990). Science for All Americans . New York, NY: Oxford University Press.
- Students should understand what rocks are and that rocks and minerals can be classified and identified based on their physical characteristics. In the early grades, it's important that students understand the difference between natural rocks and minerals, and man-made structures.
MN Standard Benchmarks
184.108.40.206.1 Recognize that rocks may be uniform or made of mixtures of different minerals.
220.127.116.11.2 Describe and classify minerals based on their physical properties. For example: Streak, luster, hardness, reaction to vinegar.
- NSES Standards
- NSES Content Standard D Earth and Space Science
- Properties of earth materials, grades K-4
- Soils have properties of color and texture, capacity to retain water, and ability to support the growth of many kinds of plants, including those in our food supply.
- Structure of the earth system, grades 5-8
- 'Soil consists of weathered rocks, decomposed organic material from dead plants, animals, and bacteria. Soils are often found in layers, with each having a different chemical composition and texture.
- AAAS Atlas
- Rock is composed of different combinations of minerals. Smaller rocks come from the breakage and weathering of bedrock and larger rocks. Soil is made partly from weathered rock, partly from plant remains, and also contains many living organisms. 4C/E2 (ID: SMS-BMK-0014) Grade range: 3 - 5.
- Read "Changes in the Earth's Surface," pages 50-51; note the Rocks and Sediments conceptual strands. (Can't find this section of the book on the Internet)
- Benchmarks of Science Literacy
- Common Core Standards
- Language Arts
- 18.104.22.168 Describe the overall structure (e.g., chronology, comparison, cause/effect, problem/solution) of events, ideas, concepts, or information in a text or part of a text.
- 22.214.171.124 Interpret information presented visually, orally, or quantitatively (e.g., in charts, graphs, diagrams, time lines, animations, or interactive elements on Web pages) and explain how the information contributes to an understanding of the text in which it appears.
- Math Standards
- 126.96.36.199 Use tables, bar graphs, time lines, and Venn diagrams to display data sets. The data may include fractions or decimals. Understand that spreadsheet tables and graphs can be used to display data.
- A rock can be defined as any solid mass of minerals or mineral-like matter that occurs naturally. Students often confuse rock-like material for rocks, such as coral, which is actually made via a living process. Students will also confuse man-made substances for rocks, such as a cement block, which is not formed through geologic processes, although it is rock-like. (Keeley, uncovering student ideas V2: p 158)
- Students of all ages may hold the view that the world was always as it is now, or that any changes that have occurred must have been sudden and comprehensive.  The students in these studies did not, however, have any formal instruction on the topics investigated.  Freyberg, P. (1985). Implications across the curriculum. In Osborne, R. (Ed.), Learning in science (pp. 125-135).
Mr. Magma is planning his annual "Chocolate Rocks" unit with his fourth grade class. Mr. M. begins the class by assessing what students already know about rocks and the rock cycle. Mr. M. lets his students observe different Minnesota rocks from samples he has collected. Students learn more about the different types of rocks by visiting the Minnesota Geological Society's virtual egg carton rock collection. Mr. M. then explains that the class will conduct a simulation activity to better understand the rock cycle. First he hands out a small plastic baggie, then he places chocolate chips, butterscotch chips, and white chocolate chips into even layers in each student's baggie. (Mr. M is careful not to use peanut butter chips because of food allergies.) Mr. M. explains that the chips represent igneous rock. Students review that igneous rocks are created when molten material such as magma (within the Earth) or lava (on the surface) cools and hardens. The hot material crystallizes into different minerals (the different chips). The properties and sizes of the various crystals depend on the magma's composition and its rate of cooling. Mr. M. reviews some of the different examples of igneous rocks: Granite, Obsidian, Basalt, Pumice, Andesite, Diorite, and Rhyolite. Then Mr. M. asks the students to hold the baggies tightly in their hands. Mr. M. explains that the pressure of their hands on the baggie is representing how sedimentary rock is formed through compression. He reminds students that they learned that sedimentary rocks are made up of sediments eroded from igneous, metamorphic, other sedimentary rocks, and even the remains of dead plants and animals. These materials are deposited in layers, or strata, and then are squeezed and compressed into rock. Examples of sedimentary rocks: sandstone, shale, conglomerate, limestone, chert, coal, and gypsum. Students then look at their baggies and notice how the pressure and warmth from their hands has melted the chips, however the chips are still in clear layers or strata. Finally Mr. M. collects the baggies and adds all the contents to a pot placed over low heat. Now Mr. M. explains how metamorphic rocks are produced when sedimentary or igneous rocks are transformed by heat and/or pressure. The word "metamorphic" comes from the Greek language, which means "to change form." Examples of metamorphic rocks: marble, slate, quartzite, schist, and gneiss. Students watch as the chocolate rocks melt into a molten "lava." Mr. M. pours the molten lava out onto wax paper and students watch as it hardens into true metamorphic rock. Finally students and teacher eat their work!
Suggested Labs and Activities
- Take students outdoors on school property or on a field trip to make a rock collection.
- Have students bring rocks into class, identify rocks and creating a class rock collection.
- Have students take pictures with digital cameras of rocks they have collected and identified, pictures can then be uploaded to collaborative websites to create a virtual rock collection. This can be particularly effective if other classrooms can also contribute to the rock collection.
- Investigations in the classroom (FOSS, Initials. (2005). Earth Materials Teacher Manual . Berkeley, CA: The Lawrence Hall of Science.):
- FOSS Earth Materials Investigation 2: Scratch test. Students explore the properties of a group of minerals and investigate the property of hardness of minerals.
- FOSS Earth Materials Investigation Investigation 3: Calcite Quest. Students explore rocks to see if they contain calcite or not.
- FOSS Earth Materials Investigation 4: Take it for Granite. Students observe and organize a collection of rocks and minerals.
- Hands-on experience with different rocks and minerals is important. Students should have opportunities to see for themselves the differences in rocks and minerals through hands-on investigation. (See sample ideas above.)
- Students should have opportunities to compare and contrast natural rocks and minerals with man-made objects that younger students may mistake for rocks, such as bricks.
- Minnesota is a very important state for mining natural rock and mineral resources. Minnesota students need to be aware of the importance of mining in the state.
- Crystal: the solid form of a material that can be identified by its natural shape or pattern.
- Earth Material: the various solids, liquids, and gases that make up the earth.
- Erosion: the wearing away of earth materials by water, wind, or ice.
- Geology: the scientific study of Earth's history and structure.
- Hardness: a property of minerals that refers to the resistance of a mineral to being scratched.
- Igneous: a rock that forms from molten or melted rock.
- Metamorphic: a rock that forms into another kind of rock by heat, pressure, or both.
- Mineral: a basic earth material; a rock ingredient that cannot be physically broken down any further.
- Rock: an earth material made up of different ingredients called minerals.
- Sediment: solid matter such as sand or gravel deposited by wind, water, and ice.
- Sedimentary Rock: a layered rock formed by deposits of sediment.
- Use a Web 2.0 tool such as voice thread to create a digital rock collection. Collaborate with other classrooms around the US/world on a digital rock collection.
- Interactive Rock cycle
- ThinkQuest website all about rocks and minerals.
- Minnesota Geological Society's virtual egg carton rock collection
- MN DNR Mining resources and information
- There are endless opportunities to integrate math with any geology study. Teachers should allow students to measure and weigh the rocks in their rock collection, integrating math and science standards aligned with accurate measurement and using scientific tools to make accurate observations.
- Social studies connections include the use of natural mineral resources (Minnesota is a significant example of this). Check out the MN DNR's website about mining in MN
- Additional social studies connections relate to the use of rocks and minerals in important industry such as agriculture. Have students research how limestone and its products are used in farming and agriculture.
Assessment of Students
- Is it a Rock? Version 1 and Version 2 (Uncovering Student Ideas in Science Volume 2 p. 151 and 157) (Both are level 3 questions.)
- Six assessment questions:
- A mixture of different minerals is called? (Level 1)
a. a rock (correct answer)
b. the earth
d. a solution
- What is the difference between a rock and a mineral? (Level 2)
- Rocks are made of a number of different ingredients and those ingredients are called minerals. Minerals are pure materials that cannot be separated into different kinds of ingredients.
- If someone sent you a letter and asked you to help identify a mineral that they had found, and they told you it was about the size of their fist, would you be able to identify it? Why or why not? (Level 2)
- No, size alone is not enough information to identify a mineral.
- What is a geologist? (Level 1)
- Geologists are scientists who study the planet earth, including the earth's rocks and minerals.
- A friend brings you a piece of brick that fell off her house for your rock collection. Can you add this brick to your rock collection? How will you identify it? (Level 2)
- Although the brick is man-made and therefore not a true rock, you could add it to your collection and identify it as such.
- Two friends are arguing about a shard of clay they found in the desert. Jenna says it's a rock; Karla says "No it's not!" Who is correct? Explain your answer. (Level 2)
- Karla is correct. A shard of clay is man-made and therefore it is not a true rock.
Assessment of Teachers
Questions could be used as self-reflection or in professional development sessions.
- Is it a Rock? Version 1 and Version 2 (Uncovering Student Ideas in Science Volume 2 p. 151 and 157)
- Teachers should reflect on the following before teaching this unit: What do I already know about the processes involved in the rock cycle? What do I need to know about the processes involved in the rock cycle before I begin to teach this unit?
- How is a basic knowledge of rocks and minerals important to developing an understanding of a dynamic earth?
Struggling and At-Risk
Bricks and mortar vocabulary labels (bricks are content specific vocabulary like "mineral;" mortar are words that a student might need but are not content-for this unit, examples might be "system" or "cycle") and word walls, vocabulary posters, pre-teaching accessing prior knowledge, graphic organizers-each activity needs to have reading, writing, speaking, listening components. Many of the above ELL strategies are also successful with at-risk students.
- Bricks and mortar vocabulary labels (bricks are content specific vocabulary like "mineral;" mortar are words that a student might need but are not content-for this unit, examples might be "system" or "cycle") and word walls, vocabulary posters, pre-teaching accessing prior knowledge, graphic organizers-each activity needs to have reading, writing, speaking, listening components. (Keenan).
- Additional ELL considerations (from SIOP: Making Content Comprehensible for ELLs):
- Concepts should be directly linked to students' background experience. This experience can be personal, cultural or academic.
- Links should be explicitly made between past learning and new concepts.
- Key vocabulary is emphasized. New vocabulary is presented in context. The number of vocabulary items is limited.
- Consistent use of scaffolding techniques throughout the lesson. Introduce a new concept using a lot of scaffolding and decrease support as time goes on. Restate a student's response or use think-alouds
- Use of a variety of question types, including those that promote higher level thinking skills.
The Mohs' scale of mineral hardness characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer material. Have students research the Mohs' scale. Who was Mohs? Allow students to follow an aspect of rock cycle research they are passionate about, complete an independent or small group research project (teachers provide scaffold for student research), have students create a rock collection as an at home assignment.
Classes can study rocks and rock formations that come from different countries; for example, why are diamonds found in Africa but not easily found on other continents? Many rocks/minerals can have important significance to different cultures (religion, jewelry, fashion). Teachers may be able to work with different families and cultures in their school to share this with their class (CRT). (Ladson-Billings, Gloria. (2005). Culturally relevant teaching. New York, NY: Lawrence Erlbaum Associates.)
Bricks and mortar vocabulary labels (bricks are content specific vocabulary like "mineral;" mortar are words that a student might need but are not content-for this unit, examples might be "system" or "cycle") and word walls, vocabulary posters, pre-teaching accessing prior knowledge, graphic organizers-each activity needs to have reading, writing, speaking, listening components. (Keenan)
Administrators should look for teachers to provide students with hands-on opportunities to examine and discover rocks and minerals. There are many free and low cost options for creating a classroom rock collection; teachers/schools should have one available for students to observe and examine. Administrators should be sure teachers confront student misconceptions; for example, confusing rock-like material for rocks such as coral or man-made substances (a cement block).
Send a note home to parents to create a family rock collection as an at home assignment; this is a great family activity and is especially fun to complete during summer vacation when there are opportunities to collect rocks from areas other than home. (FOSS Earth materials P. 31, this idea is not unique to FOSS.)
Study family birthstones: have students find out what month each family member was born and determine their birthstone. (FOSS Earth materials P. 23, this idea is not unique to FOSS.)
See: FOSS, Initials. (2005). Earth Materials Teacher Manual. Berkeley, CA: The Lawrence Hall of Science.