2. After UNIT VIII you should be able to: o Understand how mineral crystals acquire their shape o Understand the characteristics that define a sample as a mineral o Understand that many minerals are composed of similar elements o Understand the connections between minerals and rocks and that many rocks contain similar minerals o Utilize the ESRT to determine human uses of common minerals o Understand and be able to perform common mineral identification tests such as: o Color o Streak o Breakage (cleavage or fracture) o Hardness (Mohs Scale) o Acid test o Magnetism test o Luster o Density

3. o Element o Atom o Chemical Composition o Mineral o Rock o Organic o Inorganic o Orderly arrangement o Solidification o Lava o Magma o Igneous o Precipitate o Evaporate o Sedimentary o Metamorphic o Crystallize o Crystal o Appearance o Hardness o Mohs Scale o Luster o Metallic o Non-metallic o Streak o Powdered o Crushed o Breakage o Cleavage o Fracture o Density o Mass o Volume o Acid o Reaction o Magnetic o Abrasive o Lubricant UNIT VIII vocabulary you should be able to use and understand: o Scratch o Impurities o Oxidation o Angular o Physical properties o Chemical properties

4. 5 Fundamental Mineral Characteristics  Definite chemical composition  Orderly arrangement of atoms  Naturally occurring  Inorganic  Solid

5. What is a mineral?  Minerals have a definite chemical composition unique to that mineral  The chemical properties a mineral possesses determines what humans use that mineral for  For example, the mineral gibbsite (Al(OH) 3 ) can be processed to release the aluminum atoms within it to be used in manufacturing

6. Mineral Composition and Uses  Use your ESRT page 16

7. Definite Chemical Composition  The same elements will make up the same minerals but impurities/oxidation may at times change their color  For example, table salt, or halite, is always NaCl…composed of a combination of sodium (Na) and chlorine (Cl) atoms

8. Other Mineral Uses  Jewelry  Electronics  Abrasives  Lubricants  A source of metal (ore)/other useful elements

9. What are minerals made up of?  Minerals are composed of 1 or more elements  Certain elements contribute color to minerals (such as these quartz samples), but color alone is not a definite way of identifying them  Many minerals contain the same elements  Use your ESRT to identify the elements

10. Common Mineral Uses  Use your ESRT page 16

11. Orderly Arrangement of Atoms  Atoms are arranged in an orderly fashion so that a crystal forms  This arrangement defines a mineral’s physical properties such as crystal shape, hardness, or cleavage  For example: halite crystals and the atoms that produce them

12. Atomic Arrangement and Breakage  The bonds between atoms (internal atomic arrangement) in a given mineral determine how the mineral breaks  Even, angular breakage is known as cleavage  Uneven, rough breakage is known as fracture  The cleavage of the mineral graphite allows it to slide off in sheets when pressure is applied, thus making it ideal as a material in pencil lead.

13. Naturally Occurring/Inorganic Solid  Was not produced by life processes or humans  Is not a liquid or a gas

14. How do minerals form?  Minerals crystals form due to one of several rock-forming processes found in the rock cycle  Cooling and solidification of magma/lava  Precipitating out of a solution, such as when water evaporates leaving salt (halite) behind  Undergoing heat and/or pressure to form new minerals

15. Rocks are made up of 1 or more minerals  This granite has several minerals within it

16. Identifying minerals can be difficult, however many minerals can be identified with a combination of simple tests. Mineral Identification: Appearance (color)  Color and appearance can help identify some minerals, but it is usually not enough Gold Pyrite

17. Common Colors  Use your ESRT page 16

18. Mineral Identification: Hardness  Hardness is a measure of how easily a mineral can be scratched  In our class “hard” minerals are able to scratch glass while “soft” minerals do not  Talc is a very soft mineral and can be scratched by a fingernail  Diamonds are the hardest naturally occurring material and can only be scratched by another diamond

19. Mineral Identification: Mohs Scale  The Mohs Scale assigns a number to a mineral’s hardness  A diamond is a ’10’ since it is the hardest mineral  Talc, being one of the softest, is assigned a ‘1’  Lower numbers  more easily scratched

20. Hardness Values of Common Minerals  Use your ESRT page 16

21. Mineral Identification: Luster  There are two types of luster we are concerned with in this course: metallic and non-metallic  Metallic luster is when a mineral appears to be made of metal  Non-metallic luster can be a variety of other colors including minerals that look like glass

22. Luster of Common Minerals  Use your ESRT page 16

23. Mineral Identification: Streak  The streak of a mineral is the powder left behind when a mineral is crushed or is rubbed against an unglazed porcelain tile

24. Streak  Use your ESRT page 16

25. Mineral Identification: Cleavage and Fracture  Cleavage and fracture describe how a mineral breaks  Cleavage is a mineral breaking along a flat plane  Fracture is uneven and random breaking

26. Breakage of Common Minerals  Use your ESRT page 16

27. Mineral Identification: Density  Determining a mineral’s density sometimes help determine what it is  Recall: Density = mass/volume

28. Mineral Identification: Reaction with Acid/Magnetic  Some minerals bubble when acid is dripped onto them  Other minerals are magnetic

29. Other Distinguishing Characteristics  Use your ESRT page 16