Materials Included In Kit

Additional Materials Required

Prelab Preparation

1. Using a paper cutter or scissors, cut apart each set of 24 mineral playing cards. Note: If desired, laminate each sheet of What’s My Mineral? playing cards before cutting.
2. Rubber band each set of 24 mineral cards together or place each set in a resealable plastic bag.
3. Photocopy enough What’s My Mineral? Master Mineral List handouts (two per page, cut in half) so each student may have one list.
4. Photocopy enough What’s My Mineral? Game Instructions handouts and the accompanying worksheets for each student.

Teacher Tips

• This kit contains enough reusable materials for 30 students playing in pairs or for 15 student groups: 30 sets of What’s My Mineral? playing cards and 30 Mineral Properties Charts.
• If more than 30 students are in a class, students may play in teams of two and either alternate asking questions or collaborate as a team to choose questions.
• Students may have a book or folder in which to place their Master Mineral Lists to keep their respective mineral choice hidden from their opponents.
• The breakage pattern of a mineral on the What’s My Mineral? Properties Chart is classified as either fracture or cleavage. Fracture is used for those minerals that only exhibit fracture and cleavage for those that exhibit definite cleavage.
• This game is a great differentiated instructional tool to use with an introduction to mineral properties or as reinforcement after students are familiar with the properties of minerals.
• The What’s My Mineral? game is suitable for many levels from middle school to high school. The types of questions asked depend on the skill levels of the students and the curriculum. If desired, students may add more details to the Mineral Properties chart, such as the type of cleavage or fracture exhibited by the minerals.
• Game-playing in the classroom has several benefits. In addition to reinforcing science concepts, critical thinking skills are employed as students develop strategies for the types of questions to ask while playing the game. Students also learn from one another while engaging in play in a structured learning environment.
• Flinn Scientific’s Be a Mineral Detective Kit (Catalog No. AP5949) is a great hands-on activity to complement the What’s My Mineral? game. Students are challenged to identify eight different mineral samples by conducting various laboratory tests.

Answers to Prelab Questions

1. List the following questions from least specific to most specific. Which would be the best question to ask near the beginning of the game? Explain your choice.
   1. Is the hardness of your mineral less than 5?
   2. Is your mineral sulfur?
   3. Does your mineral break with a cleavage pattern?

      The questions from least specific to most specific are c, a, and b. The best question to ask near the beginning of the game is the most general question, c, in which case a yes or no answer would eliminate half of the original 24 minerals. More specific questions have a greater chance of eliminating only a few possibilities.
      Asking the most specific question only has a 1 in 24 chance of being correct and would result in a penalty if incorrect.

2. Player one’s mystery mineral is copper. Explain how player one should answer if the opponent asks, “Will galena scratch your mineral?”

   Galena has a hardness of 2.5 and the hardness of copper is listed as 2.5–3. If a particular sample of copper has a hardness greater than 2.5, then galena would not scratch it, but a sample whose hardness is 2.5 would be scratched (minerals of equal hardness will scratch each other). Since the answer to the question is sometimes, player one should respond with yes.

3. What is the penalty for an incorrect guess? Why might a player choose to take that risk?

   The penalty for an incorrect guess is the loss of a turn, allowing one’s opponent to ask two questions in a row. Guessing the mystery mineral before the answer is certain may be worth the risk if one’s opponent has eliminated all but one possibility and could win on the next turn.

Answers to Questions

1. Why can’t a mineral be classified by color alone?

   Many different minerals may have the same color, trace impurities may give minerals different colors, and minerals may rust or tarnish, changing their original colors.

2. Many of the 24 minerals on the properties chart have a white streak. What else do these minerals have in common?

   All of the minerals that have a white streak also have nonmetallic luster.

3. A mineral has been found that looks like gold. Describe how you would determine whether the mineral is gold or “fool’s gold.”

   A streak test could be performed. If the streak is greenish-black rather than yellow, then the mineral is fool’s gold or pyrite. A hardness test could also be performed. Pyrite would scratch a glass plate but gold would not. Note: While not included in the properties chart, some students may be aware that the specific gravity of pure gold (19.3) is much higher than pyrite (5.0).

4. The possibilities for an opponent’s mystery mineral have been narrowed down to seven minerals—apatite, biotite, kaolinite, microcline, quartz, talc, and topaz. What question could be asked that would guarantee the elimination of more than two of the remaining possibilities?

   Is the hardness of the mineral less than 5? A no answer would eliminate biotite, kaolinite, and talc.
   Is the mineral brown? A yes answer would eliminate kaolinite, microcline, and topaz.

Discussion

Minerals are natural compounds formed through geological processes. The term mineral includes not only the material’s chemical composition, but also its structure. Minerals range in composition from pure elements and simple salts to very complex silicates with various forms. To be considered a mineral the following five criteria must be met.

A mineral must:

• Be a solid.
• Occur naturally.
• Be inorganic (never alive).
• Have a definite chemical composition.
• Have its atoms arranged in an orderly (crystalline) pattern.

More than 4,000 different minerals exist on Earth! Minerals are identified by their physical and chemical properties.

Color and Luster
Color is one of the most obvious characteristics of a mineral. Even though the color of a mineral may be very noticeable, minerals usually cannot be classified on color alone—many different minerals may have the same color, trace impurities may give minerals different colors, and minerals may rust or tarnish, changing their original colors. The luster of a mineral refers to the way light is reflected from the mineral’s surface. Minerals exhibit two main types of luster—metallic and non-metallic. A mineral with a metallic luster shines like a piece of polished metal whereas a non-metallic mineral does not.

Mineral Streak
The streak of a mineral is the color of the mineral’s powder. The streak of a mineral may be different than the color of the mineral itself. Sometimes the color of the outside of a mineral is changed by contact with the air, water and other minerals.

Mineral Hardness
Hardness describes how resistant a mineral is to being scratched. Hardness is determined by either scratching the mineral with a tool such as glass or steel or using the mineral to scratch something else. A geologist named Friedrich Mohs (1773–1839) developed a scale for rating the hardness of minerals (see Figure 1). On the Mohs Hardness Scale, the higher the number, the harder the mineral, with 10 being the hardest. Each mineral will scratch those with an equal or lower hardness number, but will not scratch minerals with a higher number. The numbers are for relative comparisons only and do not refer to absolute hardness. In other words, a mineral with a hardness of 4 is not twice as hard as one with a hardness of 2. Crystal System
Nearly all minerals have a definite crystal structure. Crystals are solids in which the atoms are arranged in an orderly repeating pattern. The six crystal patterns that may be seen in minerals are cubic, tetragonal, hexagonal, orthorhombic, monoclinic, and triclinic (see Figure 2). Even though the crystal structure is present at the atomic level, the smooth, external faces usually associated with crystals are not always visible in minerals. Only minerals that have formed with room to “grow” will exhibit a characteristic crystal pattern and even then irregularities are often present. Breakage Pattern
Cleavage is the tendency of minerals to break along preferred directions or definite planes. Some minerals cleave in only one direction and others may exhibit two- or three-directional cleavage. Fracture is the irregular breakage of a mineral with no discernible cleavage planes. Most minerals will fracture; however, any cleavage planes present will often mask fracture patterns.

Chemical Classification
The minerals composed of pure elements are called native element minerals and are divided into two classifications—native metals (e.g., copper and silver) and native nonmetals (e.g., sulfur). Most minerals, however, are compounds and may be classified by the anion (atom with a negative charge) in the compound.

Teacher Handouts

12486_Teacher1.pdf

References

Mineralogy Database. http://webmineral.com/ (accessed August 2011).

Rocks and Minerals; St. Martin’s Press: New York, 1973.

Introduction

Learning about the properties of minerals is fun with this educational game. Students play in pairs, with each student challenged to identify the mystery mineral of an opponent, who is of course trying to do the same! The first one to discover the opponent’s mystery mineral by careful deductive reasoning is the winner.

Concepts

• Mineral properties
• Critical thinking

Experiment Overview

The purpose of this activity is to become familiar with the properties of 24 common minerals while playing a game. The objective of the game is to be the first to determine an opponent’s mystery mineral by asking a series of questions with yes or no answers. The challenge is to ask questions that will eliminate all but one possibility for the mystery mineral.

Materials

Procedure

1. Distribute the game instructions, master mineral lists, properties charts, sets of 24 mineral cards, and worksheets to each student group.
2. Go through the instructions and sample questions with the students.
3. Students may then play as many rounds of What’s My Mineral? as time allows.
4. The What’s My Mineral? Worksheet may be used as a pre- and post-game assignment.

Student Worksheet PDF

12486_Student1.pdf