Earth Science Minerals and Rocks Module 2 PDF

Senior High School NOT Earth Science Quarter 1 - Module 2 Minerals and Rocks Department of Education Republic of the Philippines Earth Science- Grade 12 Alternative Delivery Mode Quarter 1 - Module 2: Minerals and Rocks First Edition, 2020 Republic Act 8293, section 176 states that: No copyright shall subsist in any work of the Government of the Philippines. However, prior approval of the government agency or office wherein the work is created shall be necessary for exploitation of such work for profit. Such agency or office may, among other things, impose as a condition the payment of royalty. Borrowed materials (i.e., songs, stories, poems, pictures, photos, brand names, trademarks, etc.) included in this book are owned by their respective copyright holders. Every effort has been exerted to locate and seek permission to use these materials from their respective copyright owners. The publisher and authors do not represent nor claim ownership over them. Published by the Department of Education – Division of Cagayan de Oro Schools Division Superintendent: Dr. Cherry Mae L. Limbaco, CESO V Development Team of the Module Author: Rosalina B. Fantilaga Reviewers: Jean S. Macasero, Shirley Merida, Duque Caguindangan, Eleanor Rollan, Rosemarie Dullente, Marife Ramos, January Gay Valenzona, Mary Sieras, Arnold Langam, Amelito Bucod, Rosalina B. Fantilaga, Rafael Silagan Illustrators and Layout Artists: Jessica Bunane Cuňado, Kyla Mae L. Duliano Management Team Chairperson: Cherry Mae L. Limbaco, Ph.D., CESO V Schools Division Superintendent Co-Chairperson: Rowena D. Paraon, Ph.D., CESO VI Assistant Schools Division Superintendent Members Lorebina C. Carrasco, OIC-CID Chief Jean S. Macasero, EPS- Science Joel D. Potane, LRMDS Manager Lanie O. Signo, Librarian II Gemma P. Pajayon, PDO II Evelyn Q. Sumanda, School Head Cely B. Labadan, School Head Printed in the Philippines by Department of Education – Division of Cagayan de Oro City Office Address: Fr. William F. Masterson Ave Upper Balulang Cagayan de Oro Telefax: (08822)855-0048 E-mail Address: [email protected] Senior High School Earth Science Quarter 1 – Module 2 Minerals and Rocks Version 4 This instructional material was collaboratively developed and reviewed by educators from public and private schools, colleges, and or/universities. We encourage teachers and other education stakeholders to email their feedback, comments, and recommendations to the Department of Education at action@ deped.gov.ph. We value your feedback and recommendations. Department of Education Republic of the Philippines FAIR USE AND CONTENT DISCLAIMER: This module is for educational purposes only. Borrowed materials (i.e., songs, stories, poems, pictures, photos, brand names, trademarks, etc.) included in this module are owned by their respective copyright holders. The publisher and authors do not represent nor claim ownership over them. Sincerest appreciation to those who have made significant contributions to this module. Table of Contents What This Module is About...........................................................................................................i What I Need to Know.....................................................................................................................i How to Learn from this Module.....................................................................................................i Icons of this Module......................................................................................................................ii What I Know............................................................................................................... iii Lesson 1: Composition and Structure of Mineral...................................................... What I Need to Know..........................1 What I Know -------------------------2,3 What’s In---------------------------------4 What’s New: Anticipation Guide--- 4 What Is It: Learning Concept-------5 What I Have Learned: Bubble Chart..........................................................8 What I Can Do: Online Browsing and familiarize different kinds of minerals ------------------------------------------ 8 Lesson 2: Properties of Minerals................................................................................................... What’s In: Learning concept -----------------------------------------------------9 What’s New: Examine the pictures --------------------------------------------9 What’s In: Learning Activity #3.........................................................-13 What I Have Learned: Venn Diagram---------------------------------------15 Lesson 3: Classification Rocks What I Need to Know--------15 What’s In: ----------------------16 What Is It: Rock Cycle----- 16 What’s New: Rock cycle Diagram ---17,18 What Is It---------------------------------------23 What I Have Learned: Word Analysis---23 What I Can Do: Visit an area of your place........................................23 Summary............................................................................................................24 Assessment: (Post-Test) --------------------------------------------------------------------25 Key to Answers................................................................................................26-27 References................................................................................-......................28 Module 2 Minerals and Rocks What This Module is About This module deals with the relationship between minerals and rocks. It is important that we gain knowledge of the materials that make up the Earth’s crust. Rocks and minerals are significant in the formation of earth as an inner planet. The minerals that we will emphasize on this module are those which are rock-forming and those which are highly important in our economy. It is necessary for use to have a good understanding of the physical and chemical properties of minerals because this will help us in identifying rock-forming minerals. By learning these earth materials, we will have a good grasp of the various earth processes. This module will help you understand the key concepts that will answer the questions pertaining to minerals as the building block of rocks and the solid materials that are the core of the earth processes. The following are the lessons contained in this module: Lesson 1- Composition and Structure of Minerals Lesson 2- Properties of Minerals Lesson 3- Classification of Rocks What I Need to Know Learning Objectives In this module, you are expected to: 1. Identify common rock-forming minerals using their physical and chemical properties (S11ES-Ib-5); 2. Classify rocks into igneous, sedimentary, and metamorphic (S11ES-Ic-6) How to Learn from this Module To achieve the objectives cited above, you are to do the following: Take your time reading the lessons carefully. Follow the directions and/or instructions in the activities and exercises diligently. Answer all the given tests and exercises. 1 Icons of this Module What I Know PRE-TEST MULTIPLE CHOICE: Directions: Read and understand each item and choose the letter of the correct answer. Place all your answers on a separate sheet of paper. 1. Which of the following is a physical property of minerals? A. chemical make-up C. fracture B. bonding formation D. viscosity 2. Which carbonate mineral reacts readily with cool, dilute hydrochloric acid to produce visible bubbles of carbon dioxide gas? A. Calcite C. Plagioclase B. Gypsum D. Quartz 2 3. What is the hardest known mineral on earth? A. Diamond C. Native gold B. Muscovite D. Silicate 4. Which common mineral is composed entirely of silicon and oxygen? A. Calcite C. Olivine B. Diamond D. Quartz 5. Which mineral is easily soluble in water at room temperature conditions? A. Diamond C. Olivine B. Halite D. Talc 6. Which element is the most abundant in the Earth's crust by weight? A. Carbon C. Oxygen B. Chlorine D. Sodium 7. Which of the following elements bonds with silicon and forming silicates? A. calcium C. oxygen B. hydrogen D. Sodium 8. Which of the following characteristics refer to the tendency of minerals to break forming smooth flat surfaces? A. cleavage C. streak B. conchoidal D. fracture 9. Which of the following is the most abundant mineral group on the Earth's crust? A. carbonates C. silicates B. oxides D. sulfides 10. Which of the following refers to ability of minerals to reflect light on its surface? A. Streak C. fluorescence B. luster D. color 11. Which of the following is said to be the most unreliable (variable) diagnostic property of minerals? A. luster C. crystal form B. hardness D. color. 12. On Mohs hardness scale, which is the softest mineral? A. apatite C. quartz B. calcite D. talc 13. Which of the following leads to formation of an igneous rock? A. at great depth within Earth C. by changes in mineral composition B. by crystallization of molten rock D. by the weathering of pre-existing rocks 14. Sedimentary rocks account for about how much in the total percentage of rocks found in all continents? A. 20 C. 50 B. 35 D. 75 3 15. Which of the following does NOT refer to sedimentary rocks? A. may contain fossils B. may be economically important C. hold important clues to Earth's history D. formed because of heat and pressure at depths Lesson Composition and Structure of 1 Minerals What’s In Question? Are the minerals present in dietary supplements and the minerals we are talking about here the same? The answer is No. From geologic perspective, a mineral must be naturally occurring crystalline solid. Minerals found in dietary supplements are human-made inorganic compounds that contain elements needed to sustain life. These dietary minerals typically contain elements that are metals- calcium, potassium, phosphorus magnesium, and iron. Although these two types of “minerals” are different, they are related. The sources of the elements used to make dietary supplements are in fact the naturally occurring minerals on Earth’s crust. It should also be noted that vitamins are organic compounds produced by living organisms, not inorganic compounds, like minerals. What’s New Learning Activity # 1: ANTICIPATION GUIDE Minerals Write Yes if the statement is true, otherwise, No if the statement is not correct. Write your answer in the pre-reading column. You are given only 5 minutes to answer the statement below. Do not answer the post reading yet. You can answer the post reading column after you have read the characteristics of minerals below. After reading the text, then answer the post reading portion. Then compare your answer. Note: Write your answer in a separate sheet of paper. Pre-Reading Statements Post Reading (write your answer (write your before reading answer after 4 The reading the text text below) below) 1. Is a mineral solid? 1. 2. Is a mineral naturally occurring crystalline materials? 2. 3. Is a mineral having definite chemical composition? 3. 4. Is a mineral organic substance? 4. 5. Is a mineral an aggregate of rock? 5. Congratulations!!!!!!!!!!!!!!!!!!!!!!!!!!!!! What Is It Learning Concept Minerals are the building blocks of rocks. Geologists define minerals as any present inorganic solids that possess an orderly crystalline structure and a well- defined chemical composition. A mineral must exhibit the following characteristics: orderly naturally crystalline occurring structure inorganic substance substance (was never alive) a solid chemical composition Minerals exhibit the following characteristics: 1. Naturally occurring: Minerals form through natural processes, including volcanic eruptions, precipitation of a solid out of a liquid, and weathering of pre-existing minerals. Synthetic diamonds and rubies, and other substances with a specific chemical composition and structure produced by chemists, engineers, and manufacturers are not considered true minerals. 2. Solid: A true mineral must be solid at temperatures encountered at the earth’s surface. Liquids and gases are not considered minerals, they do not have a characteristic crystal structure. Ice for example ceases to exist as a mineral upon melting into liquid water. 3. Inorganic processes: Any material produced through organic activity – such as leaves, bones, peat, shell, or soft animal tissue – is not considered a mineral. Most fossils, although they were once living, have generally had their living tissues completely replaced by inorganic processes after burial; thus, they are considered to be composed of minerals as well. 4. Chemical composition: Most minerals exist as chemical compounds composed of two or more elements. The chemical formula of salt, or halite, is NaCl. A few minerals, consist of only one type of atom such as graphite (carbon, in this case), therefore, the 5 chemical formula for graphite is written simply as C. All minerals are defined by their chemical composition. Quartz, for example, has the chemical formula SiO2.The gemstone amethyst is a form of quartz that is colored pale to deep purple by the presence of the impurity Iron (Fe). Figure 1: An example of rose quartz Figure 2: Quartz (amethyst) 5. Orderly crystalline structure: Minerals are crystalline substance which means the chemical composition of a mineral is reflected internally in a regular, repeating arrangement of atoms, called the crystal structure of the mineral. The crystal structure of halite is shown in Figure 2a and Figure 2b is cubic shape. The cubic shape of salt crystals very clearly reflects the right-angle bonds between the Sodium (Na) and Chlorine (Cl) atoms in its atomic structure. Figure 2a: structure of sodium Figure 2b: The cubic shape of salt chloride crystal crystals results from the regular crystal Through organic and inorganic processes, minerals are formed. A few naturally occurring substances called mineraloids have characteristic chemical compositions but are amorphous (having no definite shape). Opal is an example. Terms to remember: 1. inorganic processes- are found naturally in the ground after the burial of the living materials e.g. salt or calcium carbonate (from shells and corals reefs). 2. crystal structure – the atoms of a mineral must be arranged in a definite pattern such as quartz. 3. chemical composition – a mineral is composed of two or more elements. THE COMPOSITION OF MINERALS There are approximately 4000 known minerals, uniquely defined by their chemical composition and internal structure. From the previous texts, you are now familiar with minerals such as quartz, halite (rock salt), gold, and diamond. Many materials found on the Earth’s surface are not minerals. Water (H2O(l)) is not mineral because it's not a solid though having the same chemical formula with ice. Coal is not a mineral because it is made up of plant remains, it lacks a particular composition, and its atoms are not arranged in an orderly way. Although they are produced by living things, the shells of 6 such marine animals as clams are composed of minerals. Out of all the elements found on Earth, only eight (8) make up 98.5 percent of the crust’s total mass. These elements, which are the ones most common in minerals, are listed in the table below. More than 90 percent of the minerals on the Earth’s crust are compounds containing oxygen and silicon, the two most abundant elements. Most minerals are compounds. Quartz is a compound of Silicon and Oxygen. The mineral galena is a compound of Lead and Sulfur. A few minerals, however, contains single elements and are called native elements, these are minerals that exists in their purest forms. Some of which include, Silver (Ag), Copper (Cu), Sulfur (S), and Diamond (C). Often, differing types of minerals (compounds and native elements) are found mixed together. Such mixtures of minerals are called rocks. The precise chemical composition and internal atomic structure that defines each mineral also directly determines its outward appearance and physical properties. Thus, in most cases, general appearance and a couple of easily determined physical properties are sufficient to spot the mineral. Common Elements of Earth’s Crust Name Percent by Element Symbol Mass Oxygen O 46.6 Silicon Si 27.7 Aluminum Al 8.1 Iron Fe 5.0 Calcium Ca 3.6 Sodium Na 2.8 Potassium K 3.6 Magnesium Mg 2.1 Other - 1.5 THE STRUCTURE OF MINERALS A mineral is composed of an ordered array of atoms chemically bonded to make a particular crystalline structure. This orderly packing of atoms is reflected in the regularly shaped objects we call crystals. Rocks are considered to be a combination of one or more minerals. The growth of crystals is affected by competition for space. The following are some of the defining features of a crystal.  Crystal structure  Regular, geometric, smooth faces  Orderly arrangements with repeating structures  Each mineral always forms the same crystal shape  Crystallographic axes are used to determine structure Six basic crystal shapes 7 What I Have Learned Learning Activity no.2: Bubble Chart 1. Instruction: In your paper, copy the bubble chart and fill in the circles in the bubble chart with the characteristics of minerals that you have just learned. Minerals What I Can Do Online Browsing and familiarize the different kinds of minerals 8 Lesson Properties of Minerals 2 What’s In Learning Concept Now that you have gained knowledge about minerals, it is time for you to know about the properties of minerals. Take note of the following points:  Minerals are identified using a set of properties.  Looking at more than one property is important when identifying minerals. At the end of this lesson, you should be able to:  Identify a mineral by using their physical properties such as color, luster, streak, cleavage, and hardness etc.  Compare and contrast the minerals by using their properties physical and chemical properties. Understand that it is necessary to examine more than one property to identify a mineral. What’s New Examine the pictures below. C an you identify these minerals by simply looking at them? PHYSICAL PROPERTIES OF MINERALS Minerals differ from each other in chemical composition and architecture, and these factors produce distinctive physical properties that enable minerals to be identified Minerals are solids formed primarily by inorganic processes. Each mineral has an orderly arrangement of atoms (crystalline structure) and a particular chemical 9 composition, which provides it a singular set of physical properties. Minerals can be identified by their color, luster, streak, cleavage, hardness, and even by their chemical composition. Using these properties is one way a Geologist defines and identifies what kind of mineral a specimen is. 1. Crystal form – The external expression of a mineral that reflects the orderly internal arrangement of atoms. A crystal may be a solid, homogeneous, displaying an orderly array of atoms and should be in any size. The shape of a mineral’s crystal is determined by the arrangement of atoms within it. Some crystals have smooth, planar and regular geometric shapes. These are what most people think of as crystals. These crystals rarely occur in nature, however, to develop those beautifully-shaped crystals, the mineral must have unlimited space for growing. When minerals start to form solid structure, microscopic crystals form and grow. This results from the cooling of molten material or through precipitation from a solution. These tiny crystals will continue to grow until they run out of space. Their shape will simply reflect the form of the void which they grew. A nicely shaped crystal such as a geode will be formed if the growing crystal runs out of material before it runs out of space. Examples of which will include pyrite and quartz. A. Pyrite B. Quartz (variety: amethyst) C. Quartz (variety: white) 2. Luster – This property describes the appearance of a mineral when light is reflected from its surface. Is it shiny or dull: does it appear as like a metal or like glass? Generally, the first thing you notice when identifying an unknown sample is the mineral’s luster. Minerals that have the appearance of metals, regardless of color, are said to have a metallic luster, like pyrite crystals. Minerals with a nonmetallic luster are described by various adjectives. They may be described as vitreous (glassy -like crystals), pearly, silky, resinous, and earthy (dull). Some minerals appear somewhat metallic in luster and are said to be sub-metallic. Minerals with a metallic luster look like metals such as steel or Copper. They possess characteristics of being shiny and opaque, even when watching through a skinny edge. Many metallic minerals become dull or earthy when they are exposed to the elements for a long time (like Silver, they tarnish). To determine whether or not a mineral exhibits a metallic luster, you may want to check out a recently broken part of the mineral and exposed it to light. Minerals with an earthy luster exhibits earth or dirt like features. Like metallic minerals, these are completely opaque, but dull. One example is rust on Iron or tarnish that forms on metals. Vitreous luster is like that of a shiny glass which may vary from translucent to transparent. Remember that glass can be almost any color, including black, so don't be fooled by the color. Also, a dark piece of glass may appear to be opaque if its thick enough. If you hold a thin edge up to the 10 light you should be able to see light bleeding through. Minerals with a waxy luster look like paraffin, typically translucent but dull. Moreover, minerals with pearly luster have an appearance almost like a pearl or that of an abalone shell – translucent and glossy. When exposed to sunlight, a rainbow effect is displayed on the surface (similar to anoil slick). A. Pyrite B. This rock contain gold & copper 3. Color – This is the most obvious feature of a mineral but often an unreliable diagnostic property. Many minerals are found in several colors. This is may be attributed to the impurities added to the minerals. Some may have extra chemicalsin them that give them an unexpected color. One good example is quartz. Due to impurities, quartz may have variety of colors including pink, purple (amethyst), milky white, and even black. Quartz (white & amethyst) 4. Streak – This color of the mineral in its powdered form, which may or may not be the same color as the outward color of the mineral. Streak is useful for identifying minerals with metallic or earthy luster. Streak is obtained by scratching the mineral on an unpolished piece of white porcelain called a streak plate. When the mineral is rubbed across the plate, it produces a powder of that mineral, the reason that the streak plate is harder than most minerals. When the excess powder is blown away, what remains is the true color of the mineral. Streaking reveals the internal color of the mineral thus it is more reliable than color in identifying minerals. 5. Hardness – This refers to a measure of the resistance of a mineral to abrasion or scratching. Geologists use a standard hardness scale, called the Mohs scale. It consists of 10 minerals arranged in order from 10 (hardest) to 1 (softest). Table: Mohs scale of mineral hardness Relative Scale Mineral Hardness of Some Common Objects Hardest 10 Diamond 9 Corundum 8 Topaz 8.5 Masonry Drill bit 11 7 Quartz 6 Potassium Feldspar 5.5 Glass, Pocketknife 5 Apatite 4 Fluorite 3 Calcite 3.5 Copper Penny 2 Gypsum 2.5 Fingernail Softest 1 Talc 1. Cleavage – A mineral that exhibits cleavage consistently breaks, or cleaves, along parallel flat surfaces called cleavage planes. Some examples are Figure 2.15 Common cleavage directions exhibited by minerals. (Photos courtesy of E. J. Tarbuck) 2. Fracture – Minerals that don't exhibit cleavage when broken have exhibits fracture like quartz. Minerals that break into smooth curved surfaces like those seen in broken glass have a conchoidal fracture. Others break into splinters or fibers, like asbestos, but most minerals fracture irregularly. Fractures are generally rough or irregular, instead of flat, and thus appear duller than cleavage surfaces. Some minerals fracture in a way that helps spot them. There are other kinds of fracture that exist in nature such as fibrous, splintery, or irregular. 3. Specific gravity –The specific gravity of a mineral is the weight of that mineral divided by the weight of an equal volume of water. The specific gravity of water equals 1.0, by definition. Most silicate, or rock-forming, minerals have specific gravities of two.6 to 3.4; the ore minerals are usually heavier, with specific gravities of 5 to eight. If you compare similar-sized samples of two different minerals, the one with the higher specific gravity will feel the heaviest; it has a greater heft. For most minerals, relative density isn't a very noteworthy feature, except for some, high relative density is distinctive (examples are barite and galena). The average specific gravity for mineral is around 2.7. 4. Other properties a. Taste – The salty taste if halite makes it easy to identify 12 b. Smell – Sulfur smells like rotten-egg. c. Elasticity –A thin sheet of mica will bend and elastically snapback d. Malleability- Gold for example is widely use because of its ability to be hammered and turn into sheets. e. Feel – Minerals like talc and graphite are easily identified due to the distinct feeling they give to the observer; talc feels soapy while graphite feels greasy f. Magnetism – Some minerals with high Iron content like hematite can easily be identified using a magnetite. g. Double refraction – Some mineral like the transparent calcite exhibits double refraction when light passes through them. When a printed material is placed under it, the text will appear double. h. Reaction to hydrochloric acid – Like calcite and other carbonates, some minerals react rapidly to weak acids. When exposed to acids, these minerals will effervesce (fizz) indicating the release of Carbon dioxide (CO2) gas. MINERAL CLASSES Approximately 4000 minerals have been named and new ones are identified each year, but only a few dozen are common. Eight elements make up the bulk of these minerals, and represent more than 98 percent (by weight) of continental crust. The eight elements that compose most rock forming minerals, are: Oxygen (O), Silicon (Si), Aluminum (Al), Iron (Fe), Calcium (Ca), Sodium (Na), Potassium (K), and Magnesium (Mg). Oxygen (46.6% by weight) and Silicon (27.7% by weight) are the most abundant elements in the crust of the earth. All silicate minerals have the silicon- oxygen tetrahedron as their fundamental building block. In some silicate minerals the tetrahedra are joined in chains; in others, the tetrahedra are arranged into sheets, or three-dimensional networks. The term ore is employed to denote useful metallic minerals, like hematite (mined for iron) and galena (mined for lead) which will be mined for a profit also as some nonmetallic minerals, like fluorite and sulfur, that contain useful substances. There are different kinds of minerals. They are classified according to their properties, chemical composition or uses. Table 2.1 lists the common groups of minerals with corresponding examples and uses. Table 2.1 Common Groups of Minerals Group Example Chemical composition uses Quartz SiO2 Magnetite Fe3O4 Source of iron Rutile TiO2 paints Hematite Fe2O3 Ore of iron, pigment Corundum Al2O3 Gemstone , abrasive Ice H2O Solid form of water Chromite FeCr2O4 Ore of chromium Oxides Ilmenite FeTiO3 Ore of titanium Limonite FeO(OH) nH2O Ore of iron, pigments Hydroxides Bauxite Al(OH)3 nH2O Ore of aluminum Sulfides Pyrite FeS2 Sulphuric acid production Galena PbS Source of lead Sphalerite ZnS Ore of zinc Chalcopyrite CuFeS2 Ore of copper Bornite Cu5FeS4 Ore of copper 13 Cinnabar HgS Ore of mercury Gypsum CaSO4.2H2O Plaster of paris Sulfates Anhydrite CaSO4 Plaster of paris Barite BaSO4 Drilling mud Gold Au Trade, Jewelries and coins Silver Ag Jewelries and coins Copper Cu Electrical conductor Diamond C Gemstone, abrasive Sulphur S Sulpha drugs chemicals Graphite C Pencil lead dry Native elements lubricant Platinum Pt Catalyst Halides Halite NaCl Common salt Fluorite CaF2 Component of steelmaking Sylvite KCl Fertilize Carbonates Calcite CaCO3 Chalk, Portland cement, lime Dolomite CaMg(CO3)2 Portland cement, lime Malachite Cu2CO3(OH)2 Gemstone Azurite Cu3(CO3)2(OH)2 Pigment Phosphates Apatite Ca5(PO4)3(OH) fertilizer Turquoise CuAl6(PO4)4(OH)8 Gemstone What’s In Learning Activity 3: PHYSICAL PROPERTIES OF MINERALS Answer the following questions: Use a separate sheet of paper. 1. In your own words, describe the following properties of minerals: Streak: Color: Hardness: Luster: Cleavage: 2. In your paper, copy and fill in the table by identifying and grouping the minerals used to demonstrate each physical property. Hematite pyrite (2) sulfur potassium feldspar calcite(2) quartz (3) biotite diamond magnetite copper fluorite (2) corundum topaz (2) talc halite galena earthy (goethite) feldspar muscovite Streak Color Hardness Luster Cleavage 14 What I Have Learned Learning Activity #4: Venn Diagram In your paper draw the Venn diagram and pick two minerals to compare. Name at least 3 similarities and 3 differences between 2 minerals. Mineral 1 Write 3 Mineral 2 Write 3 differences similarities Write 3 of of both differences Lesson Classification of Rocks 3 What I Need to Know To understand the relationship between minerals and rocks, imagining a Choco Mucho chocolate bar might just help you! It is made up of several different materials: chocolate, wafer cereal crispies coated, and caramel. A rock is like that chocolate bar. There is an aggregate of distinctive components that makes it. Mainly, these components are the minerals which you have just learned from the previous lesson. Rock components and origin are used to identify them. 15 What’s In Why study rocks? As you have learned in the previous topic, minerals are the building blocks of rocks. Rock is composed of one or more minerals. These earth materials, rocks and minerals have great economic value and the earth processes from which they originate, determine their properties. In this lesson, we will discuss the classification of rocks based on their mode of origin. Before examining each group as igneous, sedimentary and metamorphic rock, we will view first the rock cycle, which describes the interrelationships among these rock groups. What Is It Rock Cycle Fig. 1 Rock Cycle Rock Cycle To conveniently discuss the rock cycle let us begin with the formation of igneous rocks. Igneous rocks are formed by solidification and cooling of molten materials. This process called crystallization may occur either beneath the earth’s surface or following volcanic eruption at the surface. When igneous rocks make their way to the surface, they will be pick up, transported and deposited by any number of erosional agents such as running water, glaciers, wind and 16 waves. Due to these agents, the rocks will turn into sediments, which will be deposited, usually as horizontal beds in the ocean and will undergo lithification. This process where rocks experience cementation and compaction of converting the sediments into solid rock (sedimentary rocks). If the resulting sedimentary is buried deep within the earth or involved in the dynamic of mountain building, it will be subjected to great heat and pressure. The sedimentary rock will react to changing environment turn into the third type, metamorphic rock. When metamorphic rock is subjected to still greater heat and pressure, it will melt to create magma, which will eventually solidify as igneous rock. Alternative Path…. The path shown in Figure 1 is only the basic cycle; this is not the only possible path. For example, if the igneous rock did not reach the surface instead is subjected to heat and pressure beneath, it will turn into a metamorphic rock. Metamorphic rocks may be exposed to the surface and be subjected to the agents that will turn them into sediments and eventually through lithification turn them into sedimentary rocks. Sedimentary rocks may be get buried and melt turning into magma which will turn into igneous rocks. Rocks can transform from one form to another. When magma pours out on Earth's surface, magma is called lava. Lava is the same liquid rock matter that you see coming out of volcanoes. What’s New Learning Activity # 5: Rock Cycle Diagram Word Bank melting sediments igneous rock crystallization metamorphic rock metamorphism lithification heat and pressure weathering, transportation, and deposition sedimentary rock weathering and erosion 17 Complete the Rock Cycle diagram by placing terms from the word bank into the diagram. In your paper draw the diagram and write your answer. MAGMA (Molten ro)ck 1. 9. 2. 10. 8. 7. Heat & pressure 3. 11 12 4. 6. Cementation & compaction. 5. As you have learned from the discussion of the rock cycle, there are three kinds of rocks. Each has a different texture and origin. Let us find out more about these rocks. Classification of Rocks 1. Igneous rock form from magma that cools and solidifies in a process called crystallization. Crystal size depends on the rate of cooling. The faster the rate of cooling is, the smaller the crystal; this is because, there is less time for crystals of the same chemical composition to group together. On the other hand, the slower the rate of cooling, the bigger the crystal sizes are; this is because the longer time for cooling is, the more the time for crystals of the same chemical composition to group together. The texture of igneous rocks is classified into four (4): 1) fine-grained, 2) coarse-grained, 3) porphyritic, and 4) glassy. Texture among minerals refers to the size and arrangement of crystals. Types of texture Texture Description Example 1. Fine-grained fast rate of cooling Rhyolite 2.Coarse-grained slow rate of cooling Granite 18 3.Porphyritic (two two rates of cooling crystal sizes) Andesite porphyry 4. Glassy very fast rate of cooling Obsidian Igneous rocks can be categorized based on their texture and mineral composition. Felsic rocks are usually made up of the light-colored silicate minerals like Potassium feldspar and quartz. More examples of this are granite and rhyolite. Rocks of intermediate composition contain plagioclase feldspar and amphibole such as andesite. Mafic rocks (e.g. basalt) contain abundant olivine, pyroxene, and calcium feldspar Basalt Classification of Igneous Rocks Classification of Sedimentary Rocks There are two groups of sedimentary rocks based on the source of the material. 1. Detrital sedimentary rocks are formed from the accumulation of materials that originated from pre-existing rocks and was transported in the form of sediments as a result of mechanical and chemical weathering. Common examples of this rock classification include shale (most abundant), siltstone, sandstone, conglomerate or breccia. 19 Classification of detrital sedimentary rock name. Sediment name Detrital Rock name Example Gravel Conglomerate or breccia Conglomerate Sand Sandstone Sandstone Silt Siltstone Siltstone Clay Shale Shale 2. Chemical sedimentary rocks are formed when the dissolved substances from preexisting rocks are precipitated by either inorganic or organic processes. Precipitation may occur directly as the result of inorganic processes or indirectly as the result of life processes by water dwelling organism like snails and clams that produce Calcium carbonate and is said to have a biochemical origin. Common sedimentary rocks 1. Limestone is the most abundant chemical sedimentary rock. It is made up of Calcium carbonate and forms either by inorganic means or as the result of biochemical processes. “Identified Biochemical Limestone” a. Coquina is a coarse rock composed of poorly cemented shells and shell fragments. b. Chalk is a rock made up almost entirely of hard parts of microscopic organisms that are not longer than the head of a pin. c. Travertine is a form of limestone (CaCO3) that is deposited by hot springs or as a cave deposit. This type of limestone is commonly seen decorated in caverns or as a deposit when groundwater containing Calcium carbonate evaporates. 2. Microcrystalline quartz (precipitated quartz) are very small crystals which cannot be seen by the naked eye. Examples include chert (light color), flint (dark), jasper(red) and agate(banded) 3. Evaporites form eventually when the water saturated with salt evaporates but leaves the deposit behind such as rock salt and gypsum. 20 Fossiliferous limestone Coquina Chalk Rock salt 4. Coal is made up mostly of organic matter, it is the end-product of the burial of large amounts of plant material over extended periods. Lignite and bituminous coals are sedimentary rocks, but anthracite is a metamorphic rock. Anthracite is formed when bituminous coal undergoes metamorphism, and although it burns more cleanly, it is not as widespread and is more expensive to mine. Bituminous coal Classification of Sedimentary Rocks 3. Metamorphic rocks (“changed form" rocks) are formed from igneous rocks, sedimentary rocks or even from other metamorphic rocks. Metamorphism is the change in the mineral’s composition and texture of the rock when subjected to high temperature and pressure within the earth; there is transformation of pre-existing rocks. The degree of metamorphism is shown in the rock's texture and mineralogy. Types: 1. Low-grade (slight changes) e.g., shale becomes slate 21 2. High-grade (substantial changes) causes the original features to be obliterated. Metamorphic settings 1. Contact or thermal metamorphism takes place when the rock is intruded by magma. Here, change is driven by the rise in temperature within the host rock surrounding a molten igneous body. 2. Regional metamorphism occurs when a large area is affected due to large-scale heat and pressure such as mountain building. When this happens, metamorphism produces a great volume of metamorphic rocks. Agents of Metamorphism In this module, we identify three (3) agents of metamorphism, these are: (1) heat, (2) pressure or stress due to confining pressure and differential stress during mountain building, and (3) chemically active fluids (mainly water and other volatiles) which promote recrystallization by enhancing ion migration. Metamorphic textures When rocks are subjected to low-grade metamorphism, they become more compact and thus denser. A common example is the metamorphic slate. Here some types of metamorphic textures: 1. Foliated texture results in the mineral alignment perpendicular to the compressional force and usually gives the rock a layered or banded appearance. Common foliated metamorphic rock: a. Slate is a finely grained rock composed mostly of mica and produced through the low-grade metamorphism of shale. b. Schist (pronounce “shists”) is a strongly foliated rock and described as platy meaning, the rock’s crystals are thin and leaf-like". Its types are based on composition. c. Gneiss (pronounced “nice”) is a strong segregation of silicate minerals and exhibits a "banded" texture (alternating layers of light and dark minerals like granite. Slate Mica Schist Gneiss (banded appearance) 2. Non-foliated texture contains equidimensional crystals and resembles a coarse- grained igneous rock. Examples of non-foliated rocks are the following: a.Marble results when limestone (parent rock) is metamorphosed. There are large, interlocking crystals of calcite and is used as a building stone and has variety of colors. b.Quartzite forms from quartz sandstone (parent rock); quartz grains are fused. Marble – a nonfoliated metamorphic. Quartzite 22 What Is It Learning Activity # 6: Classify Me! Word Bank granite anthracite shale arkose rhyolite obsidian gypsum gneiss scoria sandstone conglomerate marble slate quartzite pumice Classify the following rocks as igneous, sedimentary and metamorphic. Find your answer from the word bank. Write your answer in a separate sheet of paper. Igneous rock Sedimentary rock Metamorphic rock What I Have Learned Learning Activity #7: Word Analysis Word Analysis. Go through the words and/or phrases in each item below and identify the relationship which is common in most of the words/phrases. Select the word or phrase which does not fit the pattern. 1. A. diorite B. gabbro C. granite D. basalt 2. A. shale B. sandstone C. breccia D. conglomerate 3. A. chemical fluids B. recrystallization C. melting D. pressure 4. A. cementation B. weathering C. lithification D. compaction 5. A. hydrolysis B. sheeting C. oxidation D. dissolution What I Can Do Learning Activity #8: Collection of Rocks (Performance Task) Visit an area in your place where you can find rocks such as rivers, parks, construction stores, etc. Collect the rocks that interest you and classify and give description of each kind of rock (classify as igneous, sedimentary or metamorphic). Request your father or relatives to accompany you to the place where you found the rocks. Ask anyone who might know the local name of the rocks and how people might have used it before or even now. Place your collected rocks in a small box and label. 23 Summary:  A mineral is a naturally occurring inorganic solid that possesses a definite chemical composition and a definitive molecular structure that gives it a unique set of physical properties. Rocks are the result of the accumulation of two or more minerals.  Characteristics of a mineral include being inorganic, solid, natural occurring, with orderly internal arrangement of particles, and has a definite chemical structure.  Rocks are a combination of one or more minerals. The growth of crystals is affected by competition for space.  A mineral is an inorganic solid that possesses a particular chemical composition and a definitive molecular structure that provides it a singular set of physical properties. Rocks are accumulations of two (2) or more minerals.  Mineral properties include crystal form, shine or luster, streak, hardness, cleavage, fracture, color, and relative density. The eight most abundant elements found in Earth's continental crust (Oxygen, Silicon, Aluminum, Iron, Calcium, Sodium, Potassium, and Magnesium) also compose the bulk of minerals.  All silicate minerals have the silicon-oxygen tetrahedron as their fundamental building block. In some silicate minerals the tetrahedra are joined in chains; in others, the tetrahedra are arranged into sheets, or three-dimensional networks. The term ore is employed to denote useful metallic minerals, like hematite (mined for iron) and galena (mined for lead) which will be mined for a profit also as some nonmetallic minerals, like fluorite and sulfur, that contain useful substances.. An igneous rock forms from magma that cools and solidifies in a process called crystallization. A sedimentary rock forms from the lithification of sediment. A metamorphic rock forms through intense pressure and heat in the process of metamorphism. The cooling rate of magma affects the size of crystals in igneous rocks– the slower the rate of cooling, the bigger the crystals, the faster the rate, the smaller the rate. The four types of igneous rock textures can be categorized as follows; 1) fine-grained, 2) coarse-grained, 3) porphyritic, and 4) glassy.  Limestone is the most common and most abundant chemical sedimentary rock, which is made up mostly of calcium carbonate.  The 2 types of metamorphism include the regional metamorphism and contact metamorphism. Heat is the most important factor which provides the energy to drive the reactions that result in the recrystallization of minerals. 24 Assessment: (Post-Test) MULTIPLE CHOICE: Directions: Read and carefully each item and choose the letter of the correct answer. Write your answers in a separate sheet of paper. 1. Which of the following properties may vary for different samples of a given mineral? A. color B. hardness C. luster D. strea 2. Which of the following is a physical property of minerals? A. chemical make-up C. fracture B. bonding formation D. viscosity 3. What is the hardest known mineral on earth? A. Diamond B. Muscovite C. Native gold D. Silicate 4. Which common mineral is composed entirely of silicon and oxygen? A. Calcite B. Diamond C. Olivine D. Quartz 5. Which mineral is easily soluble in water at room temperature conditions? A. Diamond B. Halite C. Olivine D. Talc 6. Which element is the most abundant in the Earth's crust by weight? A. Carbon B. Chlorine C. Oxygen D. Sodium 7. Which one of the following is NOT true for minerals? A. They may be liquid, solid, or gas form. B. They have a specific, internal, crystalline structure. C. They have a specific, predictable chemical composition. D. They can be identified by characteristic physical properties. 8. Which of the following characteristics refer to the tendency of minerals to break forming smooth flat surfaces? A. cleavage B. conchoida C. streak D. fracture 9. Which of the following is the most abundant mineral group on the Earth's crust? A. carbonates B. oxides C. silicates D. sulfides 10. Which of the following refers to ability of minerals to reflect light on its surface? A. Streak B. luster C. fluorescence D. color 11. Which of the following is said to be the most unreliable (variable) diagnostic property of minerals? A. luster B. hardness C. crystal form D. color. 12. On Mohs hardness scale, which is the softest mineral? A. apatite B. calcite C. quartz D. talc 13. Which one of the following is NOT one of the eight most common elements in Earth's crust? A. aluminum B. calcium C. carbon D. potassium 14. Which of the following leads to formation of an igneous rock? A. at great depth within Earth C. by changes in mineral composition B. by crystallization of molten rock D. by the weathering of pre-existing rocks 15. Sedimentary rocks account for about how much in the total percentage of rocksfound in all continents? A. 20 B. 35 C. 50 D. 75 25 Key to Answers Pre-Test 1. C 6. C 11. D 2. A 7. C 12. D 3. A 8. A 13. B 4. D 9. C 14. D 5. B 10. B 15. D Key to Answers in Lesson 1 Lesson 1: Composition and Structure of Minerals Learning Activity # 1 Learning Activity #2 Anticipation Guide Bubble Chart Post- reading 1. naturally occurring YES 2. solid YES 3. inorganic YES 4. definite chemical composition NO 5. crystalline structure NO Key to Answers in Lesson 2 Learning Activity #3: PHYSICAL PROPERTIES OF MINERALS 1. Description on the properties of minerals Streak: the colour of mineral in its powdered form Color: most reliable diagnostic property Hardness: ability of a mineral from scratching. Luster: the looks of a mineral when light is reflected from its surface. Cleavage: the capacity of a mineral to break or cleave, along parallel flat surfaces 2. identifying and grouping the minerals used to demonstrate each physical property. Streak Color Hardness Luster Cleavage hematite quartz diamond copper calcite pyrite fluorite corundum pyrite halite biotite sulfur topaz earthy (goethite) fluorite quartz talc quartz galena muscovite magnetite topaz potassium calcite feldspar feldspar Learning Activity #4: Varied answers 26 Lesson 3 Key to Answers in Learning Activity # 5: Rock Cycle diagram 1. crystallization 7. metamorphism 2. Igneous rock 8. metamorphic rock 3. Weathering, Transportation, & Deposition 9. melting 4. sediments 10. heat & pressure 5. lithification 11. weathering and erosion 6. metamorphism 12. weathering & erosion Learning Activity #6: Classify Me! Igneous rock Sedimentary rock Metamorphic rock granite gypsum anthracite rhyolite shale quartzite obsidian arkose marble pumice sandstone slate scoria conglomerate gneiss Learning Activity #7 Word Analysis 1. basalt 2. shale 3. melting 4. weathering 5.sheeting Learning Activity #8: Collection of Rocks (PT) Assessment: Post-Test 1. B 6. C 11. D 2. C 7. A 12. D 3. A 8. A 13. C 4. D 9. C 14. D 5. B 10. B 15.D 27 References: Books Tarbuck, Edward.J, Lutgens, Frederick. K. and Tasa, Dennis. 2009 Earth Science 12th ed. (Phil. Ed), PEARSON EDUCATION SOUTH ASIA PTE LTD, 81-29 Tarbuck, Edward J., Lutgens, Frederick. K. 2004 Earth Science 10 th ed(Phil. Ed). PEARSON EDUCATION SOUTH ASIA PTE LTD,. 61-19 MELC4_Project EASE Integrated Science Inside the Solid Earth: Lesson 2 Minerals and Rocks Johansson L., Alderton, Westholm, D., 2015 in Reference Module in Earth Systems and Environmental Sciences Photo: Rosalina B. Fantilaga Web Resources: http://minerals.galleries.com minerals by chemical group, name http://minerals.er.usgs.gov/minerals U.S. Geological Survey, minerals in U.S. http://www.kgs.ukans.edu/AASG Link to all state geological surveys http://geology.com minerals>rocks http://www. saddleback.edu.>notes https://www.Sciencedirect. com/mineral resources For inquiries and feedback, please write or call: Department of Education – Bureau of Learning Resources (DepEd-BLR) DepEd Division of Cagayan de Oro City Fr. William F. Masterson Ave Upper Balulang Cagayan de Oro Telefax: ((08822)855-0048 E-mail Address: [email protected] 28 29. 30 31 32 33 34 35

Earth Science Minerals and Rocks Module 2 PDF

Document Details

Tags

Related

Summary

Full Transcript

Upgrade to continue