1. Minerals Unit 3 Notes

2. What is a mineral? A mineral must be all of the following: Naturally occurring Inorganic solid (not living) Definite structure Definite composition (what it’s made of)

3. What is a crystal? A crystal is a solid in which the atoms are arranged in repeating patterns

4. Crystal Structure Here are the six crystal systems that all minerals belong to: Cubic – sylvite, halite Hexagonal – emerald, graphite Tetragonal – wulfenite, zircon Orthorhombic – topaz, sulfur Monoclinic – gypsum, mica Triclinic – kyanite, turquoise

5. Elements in Earth’s Crust

6. NameSymbol% By Mass OxygenO46.6% SiliconSi27.7% AluminumAl8.1% IronFe5.0% CalciumCa3.6% SodiumNa2.8% PotassiumK2.6% MagnesiumMg2.1% Others----1.5%

7. Mineral Composition Silicates (Si & O) Carbonates (C & O)

8. Silicates The silica tetrahedron consists of four oxygen atoms packed closely around a single silicon atom. Named for its shape (like a 3D pyramid).

9. How do minerals form? 3 Ways: –Cooling of molten rock (lava or magma) –Evaporation of liquid –Saturated solutions

10. Mineral Crystal Size Small Crystals – indicates slow cooling of molten rock Large Crystals – indicates fast cooling of molten rock

11. Mineral Identification Color – color is the first property you notice – this is usually the 1 st step in identification, but the least useful

12. Quartz and Fluorite come in many different colors

13. Mineral Identification Hardness – is a mineral’s resistance to being scratched

14. Moh’s Scale of Hardness Scale ranges from 1 to 10 1 is softest & 10 is hardest

15. Factoid What is the hardest substance on Earth?? A diamond is the hardest substance (10 on Moh’s scale)

16. 10Diamond9Corundum 8Topaz 7Quartz 6Feldspar 5Apatite 4Fluorite 3Calcite 2Gypsum 1Talc Mohs Hardness Scale

17. Mineral Identification Streak – the color of the powder left when a mineral is rubbed against a hard rough surface (usually unglazed porcelain)

18. Testing Mineral Specimens

19. Mineral Identification Luster – the way light reflects from a minerals surface

20. 2 Types of Luster Metallic – shiny Nonmetallic – glassy, brilliant, greasy, oily, waxy, silky, or pearly

21. Metallic Luster Pearly Luster (Non-Metallic) Vitreous Luster (Non-Metallic)

22. Mineral Identification Cleavage – mineral breaks along smooth surface Fracture – mineral breaks unevenly (jagged)

23. Mineral Identification Specific Gravity – comparing density of a mineral to the density of water

24. Mineral Identification Acid Test – some minerals give off CO2 (carbon dioxide) when acid is added.

25. If it’s a carbonate…

26. Mineral Usage Ore – mineral resource mined for a profit Gem – mineral that is beautiful, rare, and valuable

27. Metals Metals are elements that have metallic luster, malleability, ductility, and conductivity

28. Malleability the ability of a mineral to be hammered without breaking

29. Ductility the ability to be pulled and stretched without breaking

30. Conductivity the ability to conduct heat or electricity