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NameCHAPTER 3ClassDateMinerals of the Earth’s CrustSECTION3 The Formation, Mining, and Use of MineralsBEFORE YOU READAfter you read this section, you should be able to answerthese questions: How do minerals form? How are mineral resources used?How Do Minerals Form?Different minerals form in different environments. Thetable below shows five ways that minerals can form.ProcessDescriptionMinerals that formthis wayEvaporationWhen a body of salt waterdries up, minerals areleft behind. As the waterevaporates, the mineralscrystallize.gypsum, haliteMetamorphismHigh temperatures andpressures deep belowthe ground can cause theminerals in rock to changeinto different minerals.garnet, graphite,magnetite, talcDepositionSurface water and groundcalcite, dolomitewater carry dissolved mineralsinto lakes or seas. The mineralscan crystallize on the bottom ofthe lake or sea.ReactionWater underground can beheated by hot rock. The hotwater can dissolve someminerals and deposit otherminerals in their place.gold, copper, sulfur,pyrite, galenaMelted rock can cool slowlyunder Earth’s surface. As themelted rock cools, mineralsform.mica, feldspar, quartzCoolingSTUDY TIPDescribe As you read thissection, make a chart showing the uses of different rockand mineral resources.TAKE A LOOK1. Identify Give threeminerals that form bymetamorphism andthree minerals that formby reaction.Metamorphism:Reaction:How Are Minerals Removed from the Earth?People mine many kinds of minerals from the groundand make them into objects we need. Some mineralshave more useful materials in them than others. An oreis a rock or mineral that contains enough useful materialsfor it to be mined at a profit.There are two ways of removing ores from Earth: surface mining and subsurface mining. The type of miningused depends on how close the ore is to the surface.Copyright by Holt, Rinehart and Winston. All rights reserved.Interactive Textbook45Minerals of the Earth’s Crust

NameSECTION 3ClassDateThe Formation, Mining, and Use of Minerals continuedSURFACE MININGREADING CHECK2. Identify Give two mineralsthat are mined using open-pitmining.People use surface mining to remove ores that arenear Earth’s surface. Three types of surface minesinclude open pits, surface coal mines, and quarries.Open-pit mining is used to remove large, near-surfacedeposits of gold and copper. Explosives break up therock layers above the ore. Then, trucks haul the ore fromthe mine to a processing plant.Quarries are open mines that are used to remove sand,gravel, and crushed rock. The layers of rock near the surface are removed and used to make buildings and roads.Strip mines are often used to mine coal. The coal isremoved in large pieces. These pieces are called strips.The strips of coal may be up to 50 m wide and 1 km long.SUBSURFACE MININGREADING CHECKPeople use subsurface mining to remove ores that aredeep underground. Iron, coal, and salt can be mined insubsurface mines.3. List Give three resourcesthat can be mined usingsubsurface mining.)N SUBSURFACE MININGTUNNELS ARE DUG INTO THEGROUND 3OME OF THETUNNELS ARE HORIZONTAL 3OME SUBSURFACE MININGTUNNELS ARE DUG AT AN ANGLE #OAL BEDSTAKE A LOOK4. Identify What are threekinds of tunnels used insubsurface mining?6ERTICAL TUNNELS ARE USED TO GET TOORE THAT IS VERY FAR BELOW THE GROUND 4HEY ARE ALSO USED TO CONNECT OTHERTUNNELS WITHIN THE MINE Copyright by Holt, Rinehart and Winston. All rights reserved.Interactive Textbook46Minerals of the Earth’s Crust

NameSECTION 3ClassDateThe Formation, Mining, and Use of Minerals continuedRESPONSIBLE MININGMining can help us get the resources we need, but itcan also create problems. Mining may destroy or harmthe places where plants and animals live. The wastesfrom mining can be poisonous. They can pollute waterand air.One way to reduce these problems is to return the landto nearly its original state after mining is finished. Thisis called reclamation. Since the mid-1970s, laws haverequired the reclamation of land used for mining.Another way to reduce the problems with mining is toreduce our need for minerals that are mined. For example,when you recycle materials made from minerals, you reducethe need for further mining. If you recycle the aluminumin your soda can, less aluminum has to be removed fromthe Earth.How Are Minerals Used?We can use some minerals just as they are. However,most minerals must be processed before they can beused. The table below shows how some common minerals are used. The figure on the next page shows some ofthe processed minerals that are used in a bicycle.MineralUsesBauxite (aluminum ore)source of aluminum for cans, foil,appliances, and utensilsCopperelectrical wire, plumbing, coinsDiamondjewelry, cutting tools, drill bitsGalena (lead ore)source of lead for batteries andammunitionGoldjewelry, computers, spacecraftGypsumplaster, cement, wallboardHalitetable salt, road salt, water softenerQuartzglass, source of silicon forcomputer chipsSilverphotography, electronic products,jewelrySphalerite (zinc ore)jet aircraft, spacecraft, paintREADING CHECK5. Describe What are twoproblems with mining?READING CHECK6. Explain How canrecycling help reduce theproblems with mining?TAKE A LOOK7. Identify Give two uses forthe mineral silver and twouses for the mineral bauxite.Silver:Bauxite:Copyright by Holt, Rinehart and Winston. All rights reserved.Interactive Textbook47Minerals of the Earth’s Crust

NameSECTION 3ClassDateThe Formation, Mining, and Use of Minerals continuedMinerals Used in the Parts of a BicycleHandlebarstitanium fromilmeniteTAKE A LOOKFramealuminum frombauxite8. Identify Name fourminerals that are used in theparts of a bicycle.Spokesiron frommagnetitePedalsberylliumfrom berylMETALLIC MINERALSMany minerals contain metals. Many of the features ofmetals make them useful in aircraft, automobiles, computer parts, and spacecraft. All metals have the featuresgiven below:Critical Thinking9. Infer Electricity can passthrough metals easily. Howdoes this make metalsuseful in computers andother electronic appliances? Metals have shiny surfaces.Light cannot pass through metals.Heat and electricity can pass through metals easily.Metals can be rolled into sheets or stretched into wires.Some metals react easily with air and water. For example, iron can react with oxygen in the air to produce rust.However, many of these metallic minerals can be processed into materials that do not react with air and water.For example, iron can be used to make stainless steel,which does not rust. Other metals do not react very easily. For example, gold is used in parts of aircraft becauseit does not react with many chemicals.Many metals are strong. Their strength makes themuseful in making ships, automobiles, airplanes, and buildings. For example, tall buildings are too heavy to be supported by a wooden frame. However, steel frames cansupport skyscrapers that are hundreds of meters tall.Copyright by Holt, Rinehart and Winston. All rights reserved.Interactive Textbook48Minerals of the Earth’s Crust

NameSECTION 3ClassDateThe Formation, Mining, and Use of Minerals continuedNONMETALLIC MINERALSMany minerals also contain nonmetals. Some importantfeatures of nonmetals are given below: Nonmetals can have shiny or dull surfaces. Light can pass through some kinds of nonmetals. Heat and electricity cannot pass through nonmetals easily.Nonmetallic minerals are some of the most widelyused minerals in industry. For example, the mineral calciteis used to make concrete. The mineral quartz is used tomake glass. Quartz can also be processed to produce theelement silicon, which is used in computer chips.GEMSTONESSome nonmetallic minerals are considered valuablebecause of their beauty or rarity. These minerals arecalled gemstones. Important gemstones include diamond,ruby, sapphire, emerald, topaz, and tourmaline.Color is the feature that determines the value of agemstone. The more attractive the color, the more valuable the gemstone is. The colors of many gemstones arecaused by impurities. An impurity is a small amount ofan element not usually found in the mineral. For example, rubies and sapphires are both forms of the mineralcorundum. Rubies look red because they have chromiumimpurities. Sapphires look blue because they have ironimpurities.Most gemstones are very hard. This allows them to becut and polished easily. For example, corundum (rubiesand sapphires) and diamond are the two hardest minerals. They are also some of the most valuable gemstones.READING CHECK10. Identify Give twononmetallic minerals that areused in industry.READING CHECK11. Explain What givesmany gemstones their color?Diamonds are some of the most valuablegemstones. They are used in jewelry and inother items, such as this scepter.Copyright by Holt, Rinehart and Winston. All rights reserved.Interactive Textbook49Minerals of the Earth’s Crust

NameClassDateSection 3 ReviewSECTION VOCABULARYore a natural material whose concentration ofeconomically valuable minerals is high enoughfor the material to be mined profitablyreclamation the process of returning land to itsoriginal condition after mining is completed1. Define Write your own definition for ore.2. Describe Fill in the spaces in table to describe metals and nonmetals.Type of materialMain featuresCommon objects made from itmetalhas shiny surfacesdoes not transmit lighttransmits heat andelectricity easilycan be rolled into sheetsor stretched into wiresnonmetal3. List What are three ways minerals can form?4. Identify Give three types of surface mines and an example of the kind of materialthat each is used to mine.Copyright by Holt, Rinehart and Winston. All rights reserved.Interactive Textbook50Minerals of the Earth’s Crust