1. Chapter 3-1 Properties of Minerals. C. Welke

3. What is a mineral? Naturally occurring Inorganic Solid
Crystalline structure
Definite Chemical Composition

4. Naturally Occurring Must be formed by a process in the natural world.
Not man made.

5. Inorganic
Can not be made of a material that was once part of a living thing.

6. Solid
Always has a definite volume and a definite shape.

7. Crystal Structure
Particles line up in a pattern that repeats over and over again.
The repeating pattern of a mineral’s particles form a solid called a crystal.
A crystal has flat sides called faces.

8. Definite Chemical Composition
Always contains the certain elements in definite proportions.
Almost all minerals are crystals.
Quartz is a compound of SiO2.
Some minerals are not compounds. Copper, Silver and Gold are pure solid elements of metals.

9. Identifying Minerals
Each mineral has characteristic properties that can be used to identify it.
Color
Streak
Luster
Density
Hardness
Crystal Systems
Cleavage and Fracture
Special Properties

10. Color:
Not mineral specific

12. Streak:
The powdered form of a mineral

13. Streak A streak test can help identify a mineral.
The streak of a mineral is the color of its powder.
Mineral color may vary but its streak will not vary.
Mineral color and streak color are often different.

14. Luster:
How minerals reflect light
Metallic
Non-metallic

15. Luster can be: Metallic Glassy Waxy, Greasy or Pearly
Submetallic or Dull
Silky
Earthy

16. Density Each mineral has a characteristic density. D=M/V
Use a graduated cylinder to get the volume of an irregular solid.

17. Hardness Best clue to identify a mineral.
Is determined by a scratch test.
A mineral can scratch any mineral softer than itself, but can not be scratched by any mineral that is harder.

18. Based on Moh’s scale of hardness

19. Crystal Systems Grows atom by atom to form the minerals structure.
6 groups based on the number and angle of the crystal faces.
Crystals grown in open spaces can be perfectly formed.
Crystals grown in tight spaces can be imperfectly formed.

20. Crystal Systems Shape a mineral takes if grown unimpeded
Mineral Java Applet

21. Cleavage
Splits easily along flat surfaces.

22. Fracture
Most minerals break apart in an irregular way.

23. Cleavage & Fracture
Best identified on a fracture surface

24. Other Properties
Fluorescence – glows in the dark

25. Reactivity – reacts chemically to acid

26. Magnetism – naturally attracts metals

27. Optical Properties- bends light to produce a double image.

28. How Minerals Form
3-2
C. Welke

29. Crystallization
The process by which atoms are arranged to form a material with a crystal structure.
Can form in two ways by crystallization of molten material or by crystallization of materials dissolved in water.

30. Minerals From Magma and Lava
Magma is molten material from inside earth that hardens to form rock.
Cools slowly over many thousands of years.
Large Crystals

31. Lava is magma that reaches the Earth’s surface
Forms rock when it hardens and cools
Cool quickly and forms small crystals

32. Minerals From Solution: When elements and compounds that are dissolved in water
Minerals formed by evaporation
When water evaporates and leaves behind crystals
When ancient seas evaporated deposits of halite were left behind
Calcium and Gypsum are also formed this way

33. Minerals From Hot Water Solutions
Magma can heat underground water
The elements and compounds in the water leave the solution and crystallize when the water begins to cool
Water often flows in cracks in the rock layers
Veins occur when the water in between the rocks cool and leave behind metals or crystals

34. Using Mineral Resources
Chapter 3-3

35. Uses of Minerals
Minerals are the source of gemstones, metals, and a variety of materials used to make many products.

36. Gemstones: hard, colorful mineral that has a brilliant or glassy luster. Is durable and rare. Once cut and polished, it is called a gem. Used for jewelry, decoration, mechanical parts, and for grinding and polishing

37. Metals: Minerals such as aluminum, iron, copper or silver
Metals: Minerals such as aluminum, iron, copper or silver. Can be stretched, flattened or hammered. Are generally not as hard as gemstones

38. Uses for Minerals
Food
Medicines
Fertilizers
Building Materials

39. Producing Metals From Minerals
To produce metal from a mineral, a rock containing the mineral, called an ore, must be located through prospection and mined, or removed from the ground. Then the rock must be processed to extract the metal.

40. Prospecting
Anyone who searches, or prospects, for an ore deposit

41. Mining: 3 Types of Mines
Strip Mines: earthmoving equipment scrapes away soil to expose the ore.

42. Open Pit Mining
Miners use giant earthmoving equipment to dig a tremendous pit and removing ore deposits.

43. Shaft Mines
A network of tunnels that extend deep into the ground, following the veins of ore

44. Smelting
The process of separating the metal in the ore from the other elements that are present in the ore.

45. Alloys
A solid mixture of 2 or more elements, at least one of them a metal.
Must have the characteristic properties of a metal.
Stainless Steel is an alloy.