GOAL: Mineral identification can be boring and tedious. Most students do not have a sense of enthusiasm for rocks and minerals because identification techniques are usually taught in a format that does not engage them. The goal of this lesson is to incorporate cooperative learning and constructivism in a way that meaningfully teaches students to understand mineral properties while alleviating the tedious nature of identifying mineral specimens.

ABSTRACT: This five day lesson involves students working in cooperative groups to learn and understand the physical properties geologists use to identify minerals. The first day students will explore unknown minerals in pairs to put the properties they see into their own words. The second and third days involve students working in a group of four to become experts on two of the eight mineral identification properties and then teach their expertise to each other. The fourth day students will use a mineral flowchart to apply their understanding of mineral identification to unknown specimens. The last day of the lesson involves an assessment in which students will work with their group members to add five new unknown minerals to the previous dayís flowchart using the mineral properties they have learned.

MATERIALS: Mineral flowchart; mineral samples (graphite, galena, barite, biotite, feldspar, pyrite, muscovite, hornblende, calcite, magnetite, quartz, talc, hematite (specular and red); mineral test kit (nail, glass, streak plate, penny, magnet, hand lens, acid.

PROCEDURE: DAY 1óEXPLORATION PHASE: Students are randomly assigned to pairs (to ensure heterogeneity), given unknown mineral samples and mineral test kits and have 5-10 minutes to observe and explore. Once students have become familiar with the mineral samples, ask them to list any properties they notice that would allow them to distinguish one specimen from another.
 
With no prior knowledge of minerals, their properties, or the test kits, students begin to explore the properties of the minerals before using the test kits. Students will immediately recognize that one mineral reacts to acid (calcite), one is magnetic (magnetite), one rubs off on their fingers (graphite), and two split into thin sheets (biotite and muscovite). Allow students ample time to explore the minerals and test kits until they seem to have exhausted the properties they are able to listóand then intervene.

Going around the room, ask each student to volunteer properties they have discoveredólist them on the board. Consciously group them into one of seven properties used to identify minerals (hardness, color, luster, streak, cleavage, fracture, and other). It is important for every group to contribute at least one property, even if it is redundant. Record the language used by students in each response for future connections to scientifically accepted vocabulary. For example, students will use the terms sparkly, shiny, metallic, dull, which would be placed together for the property luster.

When students have depleted their lists, reveal the fact that they have identified most of the properties that geologists use to identify minerals. For each of their lists, identify the technical term used to describe the particular physical property of minerals. The students have generated the list of properties and now have an association for each property in their language, which has more meaning for them. They have not been subjected to a boring 50-minute lecture.

DAYS 2 & 3 CONCEPT DEVELOPMENT PHASE: The students now have personal constructs and language for each mineral property. They must now learn how to apply these properties to identify unknown minerals. Combine two student pairs to form a cooperative group of fourótry to have heterogeneous groups with all learning levels and both genders. Explain that each newly formed group will be given a packet of unknown minerals. Before the students can identify these minerals, they must first research the mineral properties they have identified as important in identifying minerals. Each member in the group is responsible for becoming an expert on two properties: fracture and cleavage, luster and magnetism, color and hardness, or streak and other.

Students spend the remainder of the period searching their books and classroom resources for explanations of their assigned properties. Group members will depend on each other to know these properties for the identification of their minerals. Also let them know that the next day they will be responsible for teaching the other members in their groups about these properties. Walk around the room to be available for answering questions or clearing up any confusion students might have as they collect information.

The following day, students break into their cooperative groups for a peer-teaching session. Each property expert explains his/her two properties to the rest of the group. When all groups have finished their instruction, assemble as a class to clarify any questions that may have arisen during the peer-teaching sessions or address common misconceptions about mineral properties. Ask pertinent questions of the groups about specific properties to check their understanding of the concepts. Possible questions include:
Are all metallic minerals magnetic? (They generally discover during their exploration that the answer is no.)
Is color a good property for mineral identification? (Students tend to agree that color is reliable, so it is important to have several color varieties of quartz available, or compare specular and red hematite.)
Would a pearly luster be considered metallic or nonmetallic? (Often students cannot make the distinction between pearly and metallic; instead they lump them together, causing future frustrations with mineral identification.)

DAY 4 APPLICATION PHASE: Students now have the tools necessary to experience the process of mineral identification. Rather than using the generalized mineral tables found in the back of the book, try using a flowchart (Figure 1) that has been developed for use with these specific mineral properties. Laminating an enlarged flowchart facilitates operation and cleanup because several minerals will mark unprotected papers.

Each cooperative group receives two flowcharts, mineral specimens, and test kits. Within their groups they work in pairs to key out the unknown specimens. Mineral samples are placed in the flowchart area marked ìAll Minerals,î and students begin to move each specimen down to the next appropriate hierarchical level until each mineral is on its respective mineral name. The two groups within the cooperative group then compare their answers to see if they have keyed each specimen to the same mineral name. Here the property experts can troubleshoot and help the group reach a consensus.

At this point circulate around the room answering questions or settling conflicts. This is a good time to address additional misconceptions as students begin discussing whether a mineral is metallic or nonmetallic. It is not critical for students to get the right answer initially; it is more important for them to understand the properties and process involved in identifying mineral samples. Once the groups have finished, discuss any problems or misconceptions they discovered they held about mineral properties.

DAY 5 ASSESSMENT: Give students five new minerals identified with their mineral names and a large, clean piece of paper. The cooperative groups must now modify the flowcharts they used in the exercise to accommodate the five new minerals. To complete this task student groups must first identify the new mineral samplesí properties and incorporate these properties into the flowchart. This activity is valuable because students demonstrate that they truly understand the systematic approach to mineral identification. Each student receives a grade based on the groupís performance.

POSITIVE INTERDEPENDENCE: Because each student in the group becomes a mini expert on two of the eight mineral identification properties, they must depend on each other to teach, learn, and understand the properties.

INDIVIDUAL ACCOUNTABILITY: Each student is responsible for researching two mineral properties and teaching those properties to the members of the group. In order for the whole group to successfully understand all eight properties, each member is held accountable for the assigned properties.

SOCIAL SKILLS: The students will develop skills of working in diverse groups, peer teaching, patience when a member is confused or misunderstands, taking turns, and listening to others.

FACE-TO-FACE INTERACTION: Students work in pairs as well as groups of four. They must work in close proximity to maximize peer teaching and learning.

HETEROGENEOUS GROUPING: Students will be placed in pairs/groups of four in such a way that maximizes heterogeneityóboth genders, different ethnicities, all learning levelsóto encourage student interaction with a wide range of other students.

EVALUATION: Students work together to incorporate five new unknown minerals into their previously used flowchart. Every student will be involved in the development of the flowchart, as each student has valuable expertise in mineral identification properties that must be used in conjunction to properly characterize the new minerals. Each student receives a grade based on the groupís performance.

PROCESSING: Students reflect on the quality of their own contribution and effort put forth when working with the group, as well as the other group membersí contributions and efforts.

Cooperative learning groups offer one vehicle for ìdealing with the negative effects on cognitive learning of the presence of othersÖthose negative effects of the presence of others tend to occur mainly under conditions of interpersonal competition or when each student is required to work alone in an unsupportive, competitive environmentî(Schmuck & Schmuck, 40). This activity gives students more control over their learning experience, allowing them the opportunity to explore together long and deeply enough so that they are comfortable with the concepts before they are asked to apply them. Not only do students become responsible for their learning and view this exercise as a challenge, but they also learn to work with a wide range of other students, enabling them to connect across differences and assisting their classmates when needed (Sapon-Shevin, 1999).
In this unit students will work together within a cooperative goal structure; the ìrespective goals of the different individual members are linked together interdependently so that a positive association exist among all membersí goal attainmentî (Schmuck & Schmuck, 207), which is understanding mineral properties and the process of mineral identification.
 
 

ADAPTED FROM: Activity from RockCamp Geology Share-a-Thon, a workshop at the NSTA Area Convention, Columbus, Ohio, November 2001.

REFERENCES:
Sapon-Shevin, M. (1999). Because we can change the world: A practical guide to building cooperative, inclusive classroom communities. Needham Heights, MA: Allyn & Bacon.

Schmuck, P.A. & Schmuck, R.A. (2001). Group processes in the classroom. New York: McGraw-Hill.
Figure 1.  Mineral Identification Flowchart
 
All Minerals

Metallic or submetallic luster

Nonmetallic luster

Reddish streak

Scratches glass

Can be scratched with a nail

Grey or black streak

Looks glittery           hematite (specular)

Breaks square or rectangular                    galena

Marks paper                   graphite

Gold color             pyrite

Magnetic                           magnetite

Black, shows cleavage            hornblende

Feels heavy             barite

Clear, splits into sheets             muscovite

Soft, scratched with a fingernail                        talc

Reacts to acid, breaks rhombic        calcite

Reddish streak           hematite (red)

Black, splits into sheets          biotite

Pink color, shows cleavage             orthoclase

Will scratch orthoclase          quartz