1. Minerals Properties of Minerals How Minerals Form Using Mineral Resources Table of Contents

2. Minerals What Is a Mineral? Mineral – naturally occurring, inorganic solid that has a crystal structure and a definite chemical composition. A substance must have 5 characteristics in order to be considered a mineral: 1.Naturally occurring – substance cannot be man made 2.Inorganic - the substance cannot form from materials that were once part of a living thing - Properties of Minerals

3. Minerals What Is a Mineral? 3.Solid – substance must be a solid with a definite volume and shape 4.Crystal - a solid in which the atoms are arranged in a pattern that repeats again and again 5.Definite Chemical Composition – the substance always contains certain elements in definite proportions

4. Minerals

5. Identifying Minerals Geologists have identified about 3,800 minerals. Each mineral has characteristic properties that can be used to identify it. Color – can be used to identify only those few minerals that always have their own characteristic color –E–Ex: Malachite is always green; Azurite is always blue

6. Minerals Identifying Minerals Streak – the color of a mineral’s powder. –O–Observe a streak by rubbing a mineral against a piece of unglazed porcelain tile –S–Streak color and mineral color are often different.

7. Minerals Identifying Minerals Luster – the way a mineral reflects light from its surface. –T–There are many different terms used to describe various lusters. They include: metallic, glassy, earthy, waxy, brilliant, and pearly

8. Minerals Identifying Minerals Density – mass in a given space or volume –N–No matter what the size of a mineral sample, the density of that mineral always remains the same.

9. Minerals Calculating Density To calculate the density of a mineral, divide the mass of the mineral sample by its volume. Density = Mass/Volume For example, if a sample of olivine has a mass of 237 g and a volume of 72 cm 3, then the density is 237 g/72 cm 3 = 3.3 g/cm 3 - Properties of Minerals

10. Minerals Calculating Density Practice Problem A sample of calcite has a mass of 324 g and a volume of 120 cm 3. What is its density? 324 g ÷ 120 cm 3 = 2.7 g/cm 3 - Properties of Minerals

11. Minerals Identifying Minerals Hardness – refers to the mineral’s ability to resist scratching. –M–Mohs hardness scale – ranks ten minerals from softest to hardest

12. MineralsTalc1Easily scratched by fingernail Gypsum2Can be scratched by fingernail Calcite3Can be scratched by copper penny Fluorite4Easily scratched with steel file/glass Apatite5Easily scratched with steel file/glass Feldspar6Scratches glass with difficulty Quartz7Easily scratches both glass and steel Topaz8Scratches quartz Corundum9No simple tests Diamond10Scratches everything

13. Identifying Minerals Crystal systems - crystals of each mineral grow atom by atom to form that mineral’s crystal structure. –C–Classified into six groups based on the number and angle of the crystal faces Cleavage – mineral’s ability to split easily along flat surfaces. –F–Fracture – the way a mineral looks when it breaks apart in an irregular way.

14. Minerals Identifying Minerals Special properties - some minerals can be identified by special physical properties –E–Ex: magnetism (Magnetite), fluorescence (Sheelite), radioactivity, reaction to acids, optical and electrical properties

15. Minerals Identifying Minerals - Properties of Minerals

16. Minerals Mineral Density Use the line graph of the mass and volume of pyrite samples to answer the questions. - Properties of Minerals

17. Minerals Mineral Density 50 g; 10 cm 3 Reading Graphs: What is the mass of Sample B? What is the volume of Sample B? - Properties of Minerals

18. Minerals Mineral Density 5 g/cm 3 Calculating: What is the density of Sample B? - Properties of Minerals

19. Minerals Mineral Density 100 g; 20 cm 3 Reading Graphs: What is the mass of Sample C? What is the volume of Sample C? - Properties of Minerals

20. Minerals Mineral Density 5 g/cm 3 Calculating: What is the density of Sample C? - Properties of Minerals

21. Minerals Mineral Density The density of samples B and C is the same. Comparing and Contrasting: Compare the density of Sample B to that of Sample C. - Properties of Minerals

22. Minerals Mineral Density 8 g Predicting: A piece of pyrite has a volume of 40 cm 3. What is its mass? - Properties of Minerals

23. Minerals Mineral Density No; Larger samples have more mass, but the ratio between mass and volume is constant. Drawing Conclusions: Does the density of a mineral depend on the size of the mineral sample? Explain. - Properties of Minerals

24. Minerals Crystal Systems Activity Click the Active Art button to open a browser window and access Active Art about crystal systems. - Properties of Minerals

25. Minerals Data Sharing Lab Click the PHSchool.com button for an activity about sharing data for the Skills Lab Finding the Density of Minerals. - Properties of Minerals

26. Minerals Where Minerals Form Minerals form on surfaces through evaporation of solutions containing dissolved minerals. Minerals form beneath surfaces when dissolved elements and compounds leave a hot water solution or when magma cools and hardens. - How Minerals Form

27. Minerals Where Minerals Form Geode – a hollow rock inside which mineral crystals have grown. Crystallization – process by which atoms are arranged to form a material with a crystal structure. - How Minerals Form

28. Minerals Minerals From Solutions Solution – a mixture in which one substance is dissolved in another. –W–When elements and compounds that are dissolved in water leave a solution, crystallization occurs. Some minerals form when solutions evaporate –E–Ex: salt crystals (Halite), Gypsum, Calcite - How Minerals Form

29. Minerals Other mineral crystals form from hot water solutions that begin to cool. –M–Many times the hot water is a result of geothermal (underground) heat –E–Ex: Silver - How Minerals Form Pure metals that crystallize from hot water solutions underground often form veins Vein – a narrow channel or slab of a mineral that is different from the surrounding rock. Minerals From Solutions

30. Minerals More on Mineral Formation Click the PHSchool.com button for an activity about mineral formation. - How Minerals Form

31. Minerals The Uses of Minerals Minerals are the source of gemstones, metals, and a variety of materials used to make many products. –G–Gemstone – a hard, colorful mineral that has a brilliant or glassy luster. Mainly used for decoration and jewelry, but can be used for grinding and polishing. - Using Mineral Resources

32. Minerals Rubies Click the Video button to watch a movie about rubies. - Using Mineral Resources

33. Minerals The Uses of Minerals –M–Metals – not as hard as gemstones but can be molded without breaking Used in building supplies, tools, framings, etc. People use materials from these minerals in foods, medicines, fertilizers, and building materials. - Using Mineral Resources

34. Minerals Producing Metals From Minerals To produce metal from a mineral: –A–A rock containing the mineral must be located through prospecting and mined (removed from the ground) –T–Then the rock must be processed to extract the metal. - Using Mineral Resources

35. Minerals Producing Metals From Minerals Ore – rock that contains a metal or economically useful mineral. Prospector – anyone who searches, or prospects, for an ore deposit. Once found, miners outline a plan for digging up the ore. There are three types of mines: –s–strip mines, open pit mines, and shaft mines - Using Mineral Resources

36. Minerals Producing Metals From Minerals Strip mine – large pieces of equipment are used to scrape away soil to expose ore Open pit – large pieces of equipment are used to dig a tremendous pit and remove ore deposits Shaft mines - have a network of tunnels that extend deep into the ground, following the veins of ore. - Using Mineral Resources

37. Minerals Links on Mining Minerals Click the SciLinks button for links on mining minerals. - Using Mineral Resources

38. Minerals Producing Metals From Minerals Smelting – an ore is mixed with other substances and then melted to separate the useful metal from the other elements the ore contains. - Using Mineral Resources

39. Minerals Producing Aluminum Click the Video button to watch a movie about producing aluminum. - Using Mineral Resources

40. Minerals Producing Metals From Minerals Once smelted, the impurities will be removed. At this point some metals can be melted together to form alloys Alloy – a solid mixture of two or more elements, at least one of which is a metal. –E–Ex: Steel - Using Mineral Resources

41. Minerals Graphic Organizer HematiteBrick Naturally occurring Crystal structure Definite chemical composition Solid Man-made No crystal structure Chemical composition varies Inorganic