1. EQ: How can I explain the
Minerals and Rocks
EQ: How can I explain the
physical and chemical properties of Minerals???
What is a Mineral?

2. Elements and Compounds in their solid form make up…
Minerals

3. A Mineral is a naturally occurring Inorganic Solid with a definite chemical composition and a crystalline structure.

4. That means that… It can’t be organic in origin It can’t be a liquid
and..
It has to have a crystal structure

5. Lets put that in a list format.
1. Minerals are a naturally occurring substance.
2. Minerals are solids.
3. Minerals have a definite chemical composition.

6. 4. The atoms that make up minerals are arranged in an orderly pattern (They form crystals).
5. Minerals are inorganic. (They were never alive and does not contain carbon.)

7. How many different minerals are there on Earth???
Answer:
About 4,000

8. More than 90% of all of the minerals in the Earth’s Crust, however, are made up of compounds containing Silicon and Oxygen, the two most abundant elements on Earth.

9. Silicates Chemical Compounds of Oxygen and Silicon
The percent composition of Silicate
Minerals in an igneous rock determine the characteristics of the rock and the magma that formed it.

10. High Silica content forms light-colored rocks.

11. While lower (but only by about 25%) Silica content forms darker-colored rocks.

13. Physical Properites
of Minerals

14. List properties of this mineral

15. With all of the different types of minerals,
how do you identify them??

16. Luster
Hardness
Streak
Cleavage
Minerals are identified and classified by visual inspection, and by performing simple tests to determine their physical properties
Color
Specific Gravity
Fracture

17. Rock-Forming Minerals

18. Only 30 of the 4,000 known minerals are common.
These 30 minerals are known as the rock-forming minerals
Rock-Forming Minerals.

19. Most rock-forming minerals are…
Silicates
The percent composition of Silicate minerals in a rock determines the type of rock it is.

20. Rocks that have a high percentage of Silicates are light in color, and are called Felsic rocks.

21. Rocks that have a low percentage of Silicates are dark in color, and are called Mafic rocks.

22. Rocks are often made of several different minerals.

23. Identifying Minerals by Inspection

24. Minerals are most often identified by inspecting their Physical and Chemical properties.

25. Color
Color is the most easily observed, but least reliable property of a mineral for identification.
This is because the color of many minerals varies with the kind of impurities in the mineral.

27. Luster
Luster is the way in which a mineral shines in the light.

28. Types of Luster
Metallic Non-Metallic

38. Streak
Streak is the color of the powder left on a streak plate when a mineral is rubbed on it.
Streak is much more reliable than color because, although the color of a mineral changes, its streak does not.

40. Cleavage
Cleavage is the tendency of a mineral to split in a particular direction.

42. “Sheety” Cleavage

44. Feldspars always cleave readily at or near right angles.

45. Fracture
Fracture is the tendency of a mineral to break in directions other than along crystal faces or cleavage surfaces.

46. Conchoidal or shell-like fracture
Fibrous facture

47. Hardness Hardness is the resistance of a mineral to being scratched.
The Mohs Hardness Scale is one of the most effective tool for identifying minerals.

52. How do Minerals Form???
1. Minerals form in cooling magma chambers

53. Different types of minerals crystallize at different temperatures
Decreasing temperature
Bowen’s Reaction Series
Mineral formation in a Magma Chamber

54. Olivine

55. Quartz

56. Pink Granite

57. Mineral Fractionalization in a Magma Chamber

58. 2. Metamorphic Minerals: Some minerals occur as the result of Recrystallisation and Reaction within existing rocks which produces new minerals in response to changes in
Pressure
and
Heat

61. 3. Some types of minerals form as water containing dissolved ions slowly evaporates.
Salt deposits

62. How long does it take for minerals to form??
Minerals in solution in water can form relatively quickly when the water evaporates.
Minerals in magma can form as quickly as the magma/lava can crystallize (lava can cool in minutes, while magma can take thousands of years).

63. Crystalline Structure
Minerals have a
Crystalline Structure

64. A regular geometric solid with smooth surfaces called….
A Crystal is….
A regular geometric solid with smooth surfaces called….
Crystal Faces

65. The orderly arrangement of ions, molecules, or atoms, in any mineral determines the shape of its crystals.

66. Although there are thousands of different types of minerals, their crystals come in six basic types of shapes

67. Cubic

68. Cubic
Looks like a cube or one die/dice

70. Orthorhombic

71. Orthorhombic The sides A, B, and C all have to be different simple
base-centered
body-centered
face-centered
                 
The sides A, B, and C all have to be different

73. Tetragonal

74. Tetragonal
A is not equal to C
It is basically a stretched out cube

76. Triclinic

77. Triclinic Similar to Orthorhombic but no angles are equal
Like a prism with unequal angles

79. Hexagonal

80. Hexagonal Looks like a hexagon
All sides are equal and all angles are equal

82. Monoclinic

83. Monoclinic
Opposite angles do not measure 90 degrees