1. Rocks And Minerals

2. II CHEMICAL COMPOSITION OF MINERALS
WHAT IS A MINERAL?

3. WHAT IS A MINERAL? A mineral occurs naturally is a solid
has definite chemical composition
has atoms arranged in orderly pattern
is inorganic - no life

4. WHAT IS A MINERAL? List the names of some minerals quartz
halite (keep your eyes off my fries)
mica
gold
diamond

5. WHAT IS A MINERAL? I said naturally occurring
Why is a pearl not considered a mineral? How about coal?
Made by an oyster
coal is organic and a sedimentary rock.
I said naturally
occurring

6. MINERALS MAY BE ELEMENTS OR COMPOUNDS
8 ELEMENTS MAKE UP 94 % OF THE EARTH’S CRUST
OXYGEN SILICON
ALUMINUM IRON
CALCIUM SODIUM
POTASSIUM MAGNESIUM

7. 3-9 MINERALS MAY BE ELEMENTS OR COMPOUNDS
What are native minerals?
Single elements minerals such as
gold
silver
copper
sulfur
diamond

8. HOW MINERALS FORM What is the size of the crystal dependant on? TIME
What are evaporates?
Minerals that form when water containing minerals evaporates.

9. HOW MINERALS FORM List three more ways minerals can form: heat
pressure
chemical action of water

10. MINERALS HAVE CRYSTALLINE STRUCTURE
A crystal is a regular geometric solid with smooth surfaces called crystal faces.
Crystals have orderly arrangement of ions and these determine the shape of the crystal.

11. MINERALS HAVE CRYSTALLINE STRUCTURE six crystal systems
CUBIC
ORTHORHOMBIC
TETRAGONAL
TRICLINIC
HEXAGONAL
MONOCLINIC

12. IDENTIFYING MINERALS 4-1 ROCK FORMING MINERALS
There are over 2000 minerals that are known.
Some rare ones include
gold
diamond

13. ROCK FORMING MINERALS Some common minerals include Quartz Feldspar
Mica
Calcite
QUARTZ
FELDSPAR
MICA
CALCITE

14. ROCK FORMING MINERALS Minerals will have crystals large or small
Minerals of the crust are considered rock forming minerals.
Minerals will have crystals large or
small

15. ROCK FORMING MINERALS Minerals have physical properties.
The study of minerals and their properties is called mineralogy.

16. IDENTIFICATION BY INSPECTION
The color, luster and crystal shape of a mineral may be observed by inspection.
Color is the first and most easily observed mineral property.
It is not a great indicator of a mineral.
Too many colors.
AMYTHEST

17. IDENTIFICATION BY INSPECTION
Why not use color?
1. Many different minerals have similar colors.
2. Traces of impurities can turn colorless minerals into colored minerals.
3. Some minerals change color when exposed to air.
(Chalcopyrite brass-yellow
to bronze in air)

18. IDENTIFICATION BY INSPECTION
LUSTER - the way a mineral shines in reflected light.
METALLIC OR NONMETALLIC
Examples of Metallic
GALENA
PYRITE

19. IDENTIFICATION BY INSPECTION
Examples of nonmetallic luster.
QUARTZ - VITREOUS
MICA - PEARLY
SPHALERITE WAX OR GLASSY LUSTER

20. IDENTIFICATION BY INSPECTION
Crystal shape - given time and room crystals form.
Mineral grain in most rocks are so small or so imperfect that crystal faces are hard to find.

21. IDENTIFICATION BY SIMPLE TESTS
The streak of a mineral is the color of its powder.
Streak is obtained by rubbing the mineral on an unglazed white tile, called a streak plate.

22. IDENTIFICATION BY SIMPLE TESTS
The streak is not always the color of the mineral.
Examples:
Iron pyrite is brass yellow.
Hematite (iron) can be red or silver.
General rule, the color of a metallic mineral is at least as dark as the hand specimen.

23. IDENTIFICATION BY SIMPLE TESTS
The streak of a nonmetallic mineral is usually colorless or white.
The sheets of muscovite
also have high heat and
electrical insulating properties
and are used to make many
electrical components.
Muscovite sheets were
used for kitchen oven windows
before synthetic materials
replaced them.
Muscovite mica

24. IDENTIFICATION BY SIMPLE TESTS
The cleavage of a mineral is its tendency to split easily or to separate along flat surfaces.
Cleavage is a useful property in mineral identification.
Examples:
Mica has one perfect cleavage.
Feldspar splits in two different directions.
Calcite and galena - three good cleavages.

25. IDENTIFICATION BY SIMPLE TESTS
Fracture - the breaking along non cleavage planes.
Examples:
Conchoidal - shell like, old coke bottles.
Fibrous or splintery - leaves jagged surface with sharp edges - native copper.
Uneven or irregular fracture - cinnabar.

26. IDENTIFICATION BY SIMPLE TESTS
Moh’s scale of hardness
1 Talc
2 Gypsum
3 Calcite
4 Fluorite
5 Apatite

27. IDENTIFICATION BY SIMPLE TESTS
I’ll have mine with a hardness of 10!!
Moh’s scale continued….
6 Feldspar
7 Quartz
8 Topaz
9 Corundum
10 Diamond

28. Specific gravity less than 3.
Specific gravity is the ratio of the weight of a mineral to the weight of an equal volume of water.
Nonmetallic minerals-Quartz
Feldspar
Calcite
Talc
Specific gravity less than 3.

29. Specific gravity about 5
Metallic minerals
Iron Ores - hematite and magnetite
Gold
Specific gravity about 5
Specific gravity of 19.3!!

30. ACID TEST Calcite is in limestone and marble.
Calcite is calcium carbonate (CaCO3)
Hydrochloric acid and calcium carbonate produces carbon dioxide gas. (fizzzzzzz)
How to make acid more reactant.
Stronger acid, heating the acid, powder the mineral.

31. SPECIAL PROPERTIES OF MINERALS
List 6 special properties of minerals.
1. Magnetic
2. Taste
3. Fluorescence
4. Phosphorescent
5. Radioactive
6. Double refraction

32. SPECIAL PROPERTIES OF MINERALS
Fluorescence is the state of glowing while under ultraviolet light.
Examples:
Fluorite
Calcite

33. SPECIAL PROPERTIES OF MINERALS
Phosphorescent - continue to glow after the ultraviolet light is turned off.
Examples:
Willemite (zinc Silicate)
Sphalerite (zinc iron sulfide)

34. 4-6 SPECIAL PROPERTIES OF MINERALS
Radioactive minerals, set off a Geiger counter.
Uranium minerals
Carnotite and uraninite
RADIOACTIVE!!

35. SPECIAL PROPERTIES OF MINERALS
Calcite - double refraction.
Calcite

36. THREE GROUPS OF ROCKS
A rock can be generally defined as a group of minerals bound together in some way.
All rocks on the crust of the Earth in one of three general ways
IGNEOUS
SEDIMENTARY
METAMORPHIC

37. This magma is HOT stuff! IGNEOUS ROCKS
Igneous rocks form by the cooling and hardening of hot molten rock from inside Earth.
This hot molten rock is called magma.
This magma is HOT stuff!

38. IGNEOUS ROCKS
Igneous rocks can form inside the earth or at the surface.
1. PLUTONIC OR INTRUSIVE igneous rocks. Cooled inside the Earth then later exposed. MAGMA
2. VOLCANIC OR EXTRUSIVE igneous rocks. Cooled outside the Earth’s crust. LAVA

39. SEDIMENTARY ROCKS
Sedimentary rocks are formed by the hardening and cementing of layers of sediments.
The sediments may consist of rock fragments, plant and animal remains, or chemicals that form on lake and ocean bottoms.

40. KINDS OF SEDIMENTS
Sedimentary rocks form when sediments form into rocks.
Three kinds of sedimentary rocks;
1. CLASTIC
2. CHEMICAL
3. ORGANIC

41. KINDS OF SEDIMENTS Clastic Formed from fragments of other rocks.
Examples
shale
sandstone
conglomerate

42. KINDS OF SEDIEMNTS Chemical
Formed from mineral grains that fall out of solution (precipitate) by evaporation or chemical action.
Examples
rock salt (halite)
limestone

43. KINDS OF SEDIEMNTS ORGANIC
Formed from the remains of plants and animals.
examples
coal
limestone formed from shells

44. I’ll show you pressure. METAMORPHIC ROCKS
Metamorphic rocks are formed when rocks that already exist are changed by heat and pressure into new kinds of rocks.
I’ll show
you pressure.

45. METAMORPHIC ROCKS Name four metamorphic rocks. 1. MARBLE 2. SLATE
3. GNEISS 4. QUARTZITE
Metamorphic rocks are rocks that have been changed through either heat or pressure or chemicals.

46. METAMORPHIC ROCKS
What igneous or sedimentary rocks is transformed into a metamorphic rock?
LIMESTONE MARBLE
SHALE SLATE
SANDSTONE QUARTZITE
GRANITE GNEISS

47. 5-22 ROCK CYCLE