Minerals: Study of Earth's Building Blocks

1. Geology (study of Earth) • Minerals • Rocks • Plate Tectonics • Earthquakes • Volcanoes • Earth’s History and Fossils (evolution) Overview 3rd and 4th nine weeks

2. Minerals Chapter 3 (orange book)Chapter 4 (green book)

3. A 1 naturally-occurring, 2 inorganic 3 solid with a 4 definite chemical composition. Study of: Mineralogy Branch of: Geology (study of the Earth) Definition

4. Definition/Rules (please consult notes) • If we melted sulfur, would it be a mineral? • If Calcite had a chemical composition of CaCO2, would it be a mineral? • If we made a diamond with PERFECT cleavage, would it be a mineral? • If a fossil had a hardness of 11, would it still be considered a mineral?

5. How many known minerals are there? • 2000? • 3000? • 4000? • 6000? • 4,900 known mineral species – according to wikipedia.com • 4,349 Total Valid Species - International Mineralogy Association • 6,293. The official list of mineral names, updated in 2009, comprises 6,293 minerals. This list, published by the Commission on New Minerals Nomenclature and Classification (CNMNC), includes not only approved minerals, but also hypothetical, questionable, discredited and unofficial minerals. The number of known minerals grows every year ‘“ according to a CNMNC annual report, about 60 new-mineral proposals are analysed each year.

6. Over 3000 identified minerals (according to textbook) • Made of elements, which can be found on the periodic table - pg. 61. Example: 1. Silicates are made of silicon and oxygen, chemical formula of SiO2 2. Halite made of sodium and Chlorine, chemical formula NaCl 3. Pure elements – sulfur, copper, gold, silver, etc. • Minerals make up rocks • Example: Granite is made of quartz, mica and feldspar

7. How many minerals exist on Earth? • How many “common” minerals are found on Earth? • What four characteristics do all minerals share? • What are minerals made of? • What do minerals combine to form? • Let’s look at the three groups of minerals… Let’s Review what we know…

8. Groups of Minerals – open to page 88 • Silicates: minerals made ofSilicon & Oxygen(SiO2) • Quartz - SiO2 • Feldspar - KAlSi3O8 • Anthophyllite - (Mg,Fe)7Si8O22(OH)2 • Carbonates: Carbonate minerals are those minerals containing the carbonate ion: CO3 • Calcite • Dolomite • Evaporites: Minerals that are formed from ions in solution being left behind as water evaporated • Halite • Gypsum

9. What two elements are most common in the Earth’s crust? • Therefore, what mineral family do you think is most abundant? • What two minerals do you think are two of the most common in the Earth’s crust? • Tables at bottom of page 88

10. Written Lab Report • Introduction & Conclusion • For each station: • Define the physical, chemical or special property from that station • Describe procedure you used and lab equipment at that station • Describe very specific results – data table if necessary • Address questions from Standard Lab Report (use it as a skeleton for your report) Advanced Lab Report –

11. Purpose: We will be identifying minerals by testing minerals’ physical properties • We will also be using: • Observations • Chemical Properties • Special Properties • Subjective – opinion, sometimes difficult to classify. • Objective – numeric – can not be argued Mineral ID Lab –

12. 1. Color - unreliable in identifying minerals *Observation/Appearance is often times NOT enough to identify a mineral – we need to test other physical properties. Physical Properties

13. (1.) Color – reliable?Calcite See why testing other physical/chemical properties is necessary!

14. Pyrite

15. Nearly 300 color variations of diamonds!

16. In a select few minerals, such as sulfur and olivine, color IS a reliable indicator. Reliable colors

17. Two main types of luster: 1. Metallic – looks shiny 2. Nonmetallic Dull, Earthy, Pearly, Vitreous, Gumdrop, Glassy, Silky, Resinous, Greasy/Oily (2.)Luster- the way a mineral reflects light

18. The color of a mineral in powder form • We use an unglazed porcelain plate to test for streak • What if the mineral shows no streak? • More reliable or less reliable than color? • Be able to name minerals that display the same, and different color/streak combinations. (3.) Streak

21. How easily a mineral can be scratched • Whose hardness scale did we use? • Moh’s Scale of hardness – pg. 91 • Hardest and softest? • We will use: • Fingernail - 2.5 • Glass - 5.5 • Streak plate – 6.5 (4.) Hardness

23. Determined by internal, atomic arrangement • Cleavage - to break along a flat surface • Fracture - to break along a jagged surface • Can a mineral have both? (5.) Cleavage and Fracture

24. Cleavage

25. Fracture Conchoidal fracture is a curved breakage

26. Calcite (CaCO3) reacts with hydrochloric Acid HCl (lower case L, not an i) • CaCO3 + HCl ---> CO2 + H2O Actual: CaCO3(s) + 2 HCl(l) → CaCl2(l) + CO2(g) + H2O(l) • Reaction shown by “effervescence” • Example of a chemical property • Safety procedures necessary at this station (6.) Acid test – identifying Carbonates

27. Effervescence

28. Specific gravity is the ratio of the density of a substance to the density of water • Density = mass/volume • Density of a solid: grams/cm3 • Density of a liquid: grams/mL • 1 cm3 = 1 mL • Specific Gravity of 19.28 means it is 19.28 times more dense than the same volume of water. (7.) Specific Gravity

29. Taste – Halite • Odor – sulfur • Magnetism – magnetite • Double refraction – Icelandic Spar Calcite • Fluorescence • Effervescence –carbonates (calcite & dolomite) Special Properties – pg. 94

30. Double Refraction

31. Fluorescence

32. In minerals formed from magma, crystal size indicates the speed the magma/lava cooled (solidified). • Large crystals – slowly • Small crystals – quickly • No crystals – very quickly Crystal Size

33. Hydrochloric Acid • Use one drop of HCl • Goggles are mandatory • Clean minerals after use • Keep station clean/dry • Hardness station - glass plate remains on lab table • No licking minerals at any other station than “taste”. Wash minerals when you’re done. • Pick up and replace ONE mineral at a time Lab Safety

34. Diamond - hardest mineral • Talc - 1 on Moh’s scale • Sulfur - example of odor & reliable color • Calcite - reacts with HCl • Halite - (NaCl) taste • Pyrite - (fool’s gold) color/streak • Magnetite - displays magnetic characteristics • Icelandic Spar Calcite – Double Refraction • Your birthstone Know these minerals!!!

35. Mine the ore A mineral is an ore if it can be mined at a profit • Processed and sometimes smelted • Refine and purify the ore • Gems often need cut/polished How do we get and use Minerals?

36. To melt (ore) in order to separate the metal contained • The ore and the valuable mineral must have different melting temperatures Smelting

37. Do not confuse smelting with smelting (catching small fish called smelt) Smelting

38. Rare and beautiful minerals • Special varieties of another mineral • Examples of gems and their common mineral forms are: • Topaz --> Topaz • Ruby --> Spinel • Emerald --> Beryl • Sapphire --> Quartz • Amethyst--> Quartz Gems or gemstones

42. Semiprecious Minerals – garnet, tanzanite, fine tourmaline, spinel, and aquamarine, Precious Minerals: diamond, ruby, sapphire and emerald, (pearl) (amethyst)

43. Diamonds - cutting, saw blades, drill bits • Quartz – electronics, time pieces, computers, semiprecious gemstone • Gems - jewelry, valuable • Some ore minerals often contain valuable elements • From these minerals we get aluminum, titanium, zinc, etc. • Graphite - pencils, lubricant • Gypsum - wallboard, cement • Sulfur – fireworks, weapons Uses of minerals and gems

44. Corundum – used for abrasives • Bauxite – aluminum ore • Halite – food seasoning and preservation • Talc – paper, ceramics Other Uses for Minerals

45. A diamond will leave a WHITE streak on a streak plate. • A gem is plentiful and ugly! • The streak plate we used in class is a glazed porcelain plate • Since gypsum has large crystals, it probably formed by cooling slowly. • A mineral is always organic. • Review: • The formula for the calcite reaction • Native minerals– what are these? True or False