lname: Date: Earth Science 11: Minerals Purpose: Text Pages: I can identify and classify minerals using their physical and chemical properties 90-111 *This is recommended reading! Matter and Atoms (5.1) Matter -Everything with mass and volume is called, which is made up of. -Elements are in turn made up of particles called. -It is important to know about the internal arrangement of atoms in a substance as this determines its properties. Earth Science 11: Minerals Page 1
Atom Structure -Because atoms are so important in shaping the properties of a mineral, it is important to know a little about them. -The nucleus contains and. -The number of protons is the atom s and is equal to the atom s number of electrons. -Electrons are charged and are found in levels around the nucleus. *The number of protons and electrons in an atom determines its properties. -Information about elements and their atoms can be found on the periodic table: -Potassium s atomic number is 19 and its most common isotope has a mass number of 39. Find its: a) # of protons b) # of neutrons c) # of electrons Earth Science 11: Minerals Page 2
Bonding of Atoms -Substances consisting of only one element are called. -Most substances are and contain atoms of elements that are chemically combined. -Why do many atoms want to form compounds? -There are three types of bonds formed by the sharing, gaining or losing of electrons: a) Covalent Bond b) Ionic Bond Earth Science 11: Minerals Page 3
c) Metallic Bonds: What is a Mineral (5.2) -A mineral is any matter with all of the following characteristics: 1. 2. 3. 4. 5. Mexico s Cueva de los Cristale How do Minerals Form? *Complete Activity 1.1 pg 2 8 Earth Science 11: Minerals Page 4
Structure of Minerals: Crystal Structure -A crystal is a geometric solid with smooth surfaces called crystal faces. -Ionic bonding between Na+ and Cl- ions results in a repeating pattern of each sodium ion being surrounded by six chlorine ions and each chlorine ion being surrounded by six sodium ions. Produces a cubic crystal (all Sodium Chloride crystals will have this shape!). -Each mineral crystal has a unique shape that can be used to identify it. Halite (NaCl): Cubic cleavage Calcite (CaCO 3): Rhombohedral cleavage -Are crystal faces always present? -Cleavage: Earth Science 11: Minerals Page 5
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Mineral Structure: Silicates -Minerals composed of and are called silicates. More than % of Earth s crust are silicates -Silica tetrahedrons are the of silicates. -Arrangement of silica tetrahedrons in a silicate determines many minerals characteristics. Write a brief note for each characteristic provided below: a) Mineral s melting/vaporizing temperature b) Mineral s cleavage c) Mineral s hardness d) Mineral s density Earth Science 11: Minerals Page 7
*Complete Mineral ID Lab (Activity 19 pg. 13) Earth Science 11: Minerals Page 8
Earth Science 11: Earth Materials, Rock Cycle Purpose: Text Pages: Describe the formation of igneous, sedimentary and metamorphic rocks and understand their positions within the rock cycle. Chapter 2, pages 44 to 46 *This is required reading! Part A: The Rock Cycle *Examine the diagram below and watch the Rock Cycle Smarfigure. Earth Science 11: Minerals Page 9
Use the table to describe the pathway the parent rock is transformed into the daughter rock: Parent Rock Pathway Daughter Rock Extrusive Igneous Weathering, erosion, deposition, lithification Sedimentary Metamorphic Melting, cooling Igneous Intrusive Igneous Metamorphism (heat and pressure) Metamorphic *Remember, all rocks are made up of minerals! *Complete Activity 2.1 pg. 28 Earth Science 11: Minerals Page 10
Earth Science 11: Earth Materials, Igneous Rocks Purpose: -Describe the formation of igneous, sedimentary and metamorphic rocks and understand their positions within the rock cycle. -Identify and classify rocks using their physical and chemical properties. Text Pages: Chapter 1, pages 46 to 53 *This is recommended reading! Part A: Formation Igneous rocks are formed by the following pathway: a) Movement of magma towards Earth s surface (magma is warm and less dense than surrounding material). b) Crystallization of magma. Atoms slow in their movement and become arranged in orderly patterns. c) Crystals grow in size until their edges meet. All liquid is eventually turned into a mass of interlocking crystals. Igneous rocks can be classified as intrusive or extrusive, depending on if they form below or above ground. Crystallization can be affected by cooling time and parent magma composition. Part B: Texture A rock s texture described the size, shape and arrangement of its mineral grains. Texture is very useful in determining the environment in which rock s formed. Earth Science 11: Minerals Page 11
*Examine the diagram below and watch the smartfigure on texture. Which of the igneous textures above best describe a rock that: a) Cooled so quickly its atoms froze in place without forming mineral crystals? -Glassy Texture b) Cooled slowly for millions of years below ground? -Coarse-grained (Phaneritic) texture. c) Began cooling slowly underground but finished crystallizing quickly when it was ejected above Earth s surface? -Porphyritic texture. d) Crystallized rapidly at Earth s surface and contained a large amount of gas or water vapour? -Fine Grained (Aphanitic) and Vesicular texture. Earth Science 11: Minerals Page 12
Use what you know about rock texture to determine the formation environment of the rocks below: Sample A Sample B Image Formation Environment (Intrusive or Extrusive) Evidence of Formation Environment Above Ground (Extrusive) -No visible mineral crystals (indications of quick cooling), termed Aphanitic Underground (Intrusive) -Large mineral crystals (indications of slow cooling, which only occurs underground), called Coarse-Grained *Complete Activity 2.2 pg. 30 Part C: Igneous Rock Families Igneous rocks are divided into four basic families based on their proportion of: a) Light silicate minerals, which are silica, potassium and sodium rich. b) Dark silicate minerals, which are iron, magnesium and calcium rich. Earth Science 11: Minerals Page 13
Remember that all minerals contain silica tetrahedrons, but in different quantities. How much silica a rock possesses can affect its overall characteristics. Below is a graph illustrating the same concept as the chart on the previous page, but with an emphasis on silica tetrahedron bonds. Earth Science 11: Minerals Page 14
1. Felsic Igneous Rocks: Granitic Felsic rocks form from magma containing a large amount (~70%) of the light silicate minerals feldspar (Fel) and silica (Sic) and little (~10%) dark silicate minerals. Identify the minerals found in the granite sample to the right. Which are light silicate minerals? -Black: Biotite. Dark Silicate. -White: Plagioclase Feldspar. Light Silicate. -White/Clear: Quartz -Salmon: Potassium Feldspar. Light Silicate. Why are Felsic rocks commonly light coloured? -Contain primarily light silicate minerals with very little iron and magnesium. Most Felsic rocks are intrusive. Why do you think this could be? -Parent magma has a high silica content. This makes them very resistant to flow as all of the silica bonds must be broken for this to happen. Only intense pressure can push felsic magma above ground and this produces violent volcanic eruptions (Mount. St. Helens). 2. Mafic Igneous Rocks: Basaltic Mafic rocks form from magma containing a large amount of the dark silicate minerals Magnesium (Ma) and Iron and little light silicate minerals. Will Mafic rocks be lighter or darker than Felsic rocks? Why? -Darker, as made up of dark coloured silicate minerals. Will Mafic rocks be heavier or denser than igneous rocks? Why? -Denser, as their components are made of heavier elements. Pumice (Felsic) Scoria (Mafoc) Earth Science 11: Minerals Page 15
3. Intermediate Igneous Rocks: Andesitic Contain a mixture of both light and dark coloured silicate minerals, but mainly plagioclase feldspar and amphibole. As such, they are commonly medium gray to green in colour. Associated with volcanic activity at the edge of continents where mafic magma mixes with felsic continental crust to form an intermediate magma. 4. Ultramafic Igneous Rocks Peridotite is the only ultramafic rock and is largely composed of olivine and pyroxene with very little light coloured silicate minerals. Ultramafic rocks are rare, but important parts of the upper mantle. Earth Science 11: Minerals Page 16
Part D: Classifying Igneous Rocks Igneous rocks are classified based on their textures and compositions. *Watch the smartfigure on Classifying Igneous Rocks. *Complete Activity 2.3 and 2.4 pg. 31-34 Earth Science 11: Minerals Page 17