1. Minerals

2. Objective: Minerals To learn the definition of a mineral
To understand what an ore is
To learn the different physical properties of minerals

3. Quickwrite: Answer one of the questions below in 1-2 sentences
What are some minerals that we use in our everyday lives?
What is the name of the mineral we use in our pencils?
How do you think we tell minerals apart?

4. Rocks:
A mixture
of minerals

5. Minerals
To determine whether a substance is a mineral or non-mineral, scientists ask four basic questions
First, is it inorganic? (Not made of living things such as coal)
Second, did the substance form naturally? (not manmade such as steel which is a combination of metals)
Third, is the substance a solid or crystalline form? (Such as the quartz up in the corner of this slide)
Finally, does the substance have a consistent chemical composition?

6. Is it a Mineral or Not? Coal Steel Halite Is it inorganic? No Yes
Granite
Halite
Is it inorganic? No
Yes
Does it occur naturally?
Is it a crystalline solid?
Does it have a consistent chemical composition?(is it pure?)

7. Mineral or not?
A mineral is a natural, inorganic solid with a definite chemical structure and composition

8. So What is a Mineral?
A mineral is a natural, _____ solid with a definite chemical structure and composition
Answer Bank
reflects
Profit
Inorganic
Flat
crystal

9. Ores
An ore is a mineral deposit that we remove form the earth for profit($$$$)
Bingham mine
Utah USA
Worlds largest
Mine

10. Examples of Some Ores Bauxite for aluminium Hematite for iron
Malachite and azurite
for copper
Sphalerite for zinc
Cinnabar for Mercury
Galena is the ore for Lead

11. What is an Ore?
An ore is a mineral deposit that we remove form the earth for _____($$$$)
Answer Bank
reflects
Profit
Inorganic
Flat
crystal

12. Physical Properties
In order to identify minerals, geologists use a minerals physical properties to help identify them
Many minerals look the same and are hard to tell apart
In order to identify them, geologists use the following physical properties to identify them:
Hardness
Luster
Color
Streak
Crystal Shape or Form
Cleavage
Special Properties

13. Which One Is It? Appearance
Never use appearance to tell minerals apart
Why? Because many mineral look very similar if not identical to each other
For example, how can we tell pyrite (fool’s gold) apart from real gold?
Or, how can we tell gold apart from copper?
Which one is gold?
Which one is copper?
Which one is pyrite?

14. Physical Properties: Hardness
One way we classify minerals is hardness
A measure of how easily a mineral can be scratched is its hardness
The mineral talc for example, can be scratched with a fingernail
Talc is so soft, we make baby powder out of it
On the other hand, diamonds, are the hardest substance know to man
A diamond can only be scratched by another diamond

15. Moh’s Hardness Scale
A mineral hardness scale (1-10) was developed by Friedrich Mohs
Mohs hardness scale has talc being the softest (1), and diamonds being the hardest (10)
This scale is used to help us identify unknown minerals
Harder minerals can scratch softer minerals
Can Topaz scratch fluorite?

16. Diamond vs. Graphite Why is graphite soft and diamond so hard?
Graphite and diamond are both made up of pure Carbon
But why is one soft and used to write with, and the other is very precious?
The answer is in the internal structure of the mineral
The chemical bonds in diamonds are very strong and rigid compared to the chemical bonds in graphite

17. Physical Properties: Luster
Another way we classify minerals is Luster
Luster is how light is reflected from a minerals surface
Many minerals have a metallic luster
Others have a vitreous or glassy Luster
Some may have a dull or pearly Luster

18. Physical Properties: Streak
Another way we classify minerals is by streak
Streak is the color of the mineral when it is broken up or in powdered form
When a mineral is rubbed against a Porcelain plate, a streak is left behind
This streak is the powdered mineral
Remember gold and pyrite?
Gold has a yellow streak and pyrite has a black streak
Hematite leaves a red streak

19. Physical Properties: Cleavage & Fracture
The way a mineral breaks is another clue to it’s identity
Minerals that break along smooth, flat mineral surfaces have cleavage
Cleavage, like hardness, is determined by the arrangement of the minerals atoms
Mica is a mineral that has perfect cleavage
Not all minerals have cleavage
Minerals that break rough and uneven have fracture (example: Quartz)

20. Physical Properties: Color
Another obvious way we tell minerals apart is by there color
However, color can be deceptive and is not an accurate way to identify a mineral!!!!!!!!!!!!!!!!!!
Some minerals like sulfur are always yellow and never change color
Most minerals like quartz can be many different colors
Impurities can cause minerals to have many different colors

21. Physical Properties: Crystal Form
Another Way we identify minerals is by there crystal shape or form
Minerals, as we know, can form into various geometric shapes
These crystal shapes are the result of the minerals internal chemistry and how they form
Each Mineral has it’s own unique crystal shape

22. Hexagonal Rhombohedral Octahedral Dodecahedral Cubic
Examples: Quartz, Corundum
Rhombohedral
Example: Calcite
Octahedral
Example: Flourite, Diamond
Dodecahedral
Example: Garnet
Cubic
Example: Pyrite, Halite

23. Physical Properties: Special Properties
Some minerals have Special Properties that make them easy to identify
Magnetite, as you might have guessed, is magnetic
Magnetite is attracted to other magnets and will change the compass needle direction
Calcite has double refraction
When light passes through calcite, it breaks light up into two directions creating a double image
Besides a bright yellow color, Sulfur has an unpleasant odor, making it easy to identify
Halite (salt) has a taste to it that also makes it easy to identify

24. Fluorescent Minerals
Fluorescence is a special property where minerals glow or give off light under Ultra violet light

25. What are a mineral’s physical properties?
Hardness: a measure of easily a mineral can be scratched
Luster: how a mineral ____ light ex. Metallic or vitreous
Color
Streak: a mineral’s color in powdered form when rubbed on a porcelain plate
Crystal Shape or Form: characteristic ____shape
Cleavage: tendency of a mineral to break along ____ planes
Fracture: mineral that break unevenly or irregular
Special Properties: odor, taste, magnetism
Answer Bank
reflects
Profit
Inorganic
Flat
geometric

26. Summarize
A mineral is a natural, ______ solid with a definite chemical structure and composition
We tell minerals apart by their physical _____
Minerals that break along flat surfaces is called ________
Magnetite is a mineral that is ________
Answer Bank
reflects
magnetic
Inorganic
properties
cleavage