1. Minerals Formation, Characteristics and Identifying Properties

2. Why study minerals? Minerals are important in our everyday lives...

5. Some Uses (from USGS web site) Drywall is made from gypsum, ■ ■ Concrete in the foundation is made with limestone and aggregate reinforced with steel rebar, ■ ■ Bricks are made from clay, ■ ■ Titanium oxide is used to make paint, ■ ■ Silica is used to make windows, ■ ■ Electrical wiring is made from copper, ■ ■ Iron and copper are used to make pipes for plumbing, and ■ ■ Faucets contain various combinations of iron, chromium, nickel, and molybdenum combined to make stainless steel.

6. So Now...What is a Mineral? A Naturally occurring InorganicHomogenousCrystalline Single solid substance

7. Asbestos All pictures are from:

8. Calcite note shape of crystal

9. Garnet NY State Mineral

10. Diamond The hardest mineral

11. So...what is a crystal? A solid with a regular geometric shape resulting from the internal arrangement of atoms which make it up 6 basic shapes

12. Crystal Shapes: Cubic (halite) Hexagonal (quartz) Orthorhombic Monoclinic (calcite) TetragonalTriclinic

14. How Do Minerals Form? Cooling of magma (crystallization) Heat and pressure (recrystallization) Evaporates or precipitates from seawater

15. What Determines the Size of the Crystal/Mineral? Cooling time coarse or large crystals have a long cooling time fine or small crystals have a short cooling time

17. Identifying Minerals: We use observable and testable characteristics to identify minerals

18. Easily Observable Characteristics: Color Luster(way the mineral reflects light) Crystal Shape

19. Testable Characteristics: Hardness (Moh’s Scale) Streak (color of mineral in powdered form) Acid Test Cleavage vs. Fracture Specific Gravity Fluorescence

20. Color This is the least reliable property to use to identify a mineral

21. Luster Metallic or Non-metallic

22. Streak Rub mineral along porcelain streak plate

23. Hardness-Moh’s Scale: use tools to test each mineral by scratching it against the tool. If the mineral can scratch the tool then it is harder

24. Cleavage vs. Fracture This is the way the mineral breaks -if it breaks along a plane then it cleaves, if it shatters then it fractures

26. Cleavage-way mineral breaks

27. Fracture

28. acid test: bubbles (releases carbon dioxide gas)

29. Special Properties Fluoresence: glows under blue light Double Refraction: see words or images twice when looking through the mineral Magnetic: will attract metals like a magnet

30. Use these tests to help you identify minerals in lab...