1. Lesson #12 Properties of Minerals
Objective: learn how to use characteristics to tell one mineral from another
Bellringer: Grab the handout from the front and have a seat. Fill out ToC, lesson, and objective in your notebook

2. Mineral Characteristics
Earth’s crust is composed of about 3000 different minerals

3. Mineral Characteristics
A mineral:
Is naturally occurring
Is inorganic solid
Has a specific chemical composition
Has definite crystalline structure

4. Mineral Characteristics
Naturally occurring and inorganic
naturally occurring - formed by natural process
inorganic - they are not from living things
Is coal a mineral?

5. Mineral Characteristics
Specific chemical composition

6. Mineral Characteristics
Definite crystalline structure
atoms are arranged in regular, repeated, geometric patterns that result in the formation of a crystal.

7. Mineral Characteristics
Definite crystalline structure
Feldspar
Diamond
Quartz
Apetite

8. Identifying Minerals
identify minerals using tests based on a mineral’s physical and chemical properties:
crystal form
luster
hardness
cleavage
fracture
streak
color
specific gravity
texture
density

9. Luster
Refers to the way light reflects from the surface of the mineral.
two types;
Metallic: looks like polished metal.
Nonmetallic: shiny or dull.

10. Pyrite has metallic luster

11. Quartz has nonmetallic luster

12. Hardness Is measured by how easy it is to scratch. order;
Scratched by a fingernail.
Scratched by a penny.
Scratched by an iron nail.
Scratched by a diamond. .

13. Gypsum is soft, it can be scratched by a fingernail.

14. Calcite is soft, but a little harder because it cannot be scratched by a fingernail, but it can be scratched by a penny.

15. Fluorite is harder. It can be scratched by a nail, but not a penny or fingernail.

16. Diamonds are the hardest mineral, so it scratches every mineral.

17. Cleavage Not all minerals have cleavage.
Some minerals split easily along a flat surface.
The number of lines that are created when split = cleavage lines.

18. Mica has cleavage in one direction. It breaks along one line.

19. Feldspar has two lines of cleavage. It breaks along two lines.

20. Fracture When minerals break along uneven, rough, or jagged edges
Think of a bone fracture

21. Fracture

22. Streak
Red chalk on a chalk board makes red marks. White chalk makes white marks.
Not all minerals work this way. When some minerals are scratched along a ceramic streak plate, it creates a different color.

23. Gold
When gold is run across a streak plate it makes a yellowish-gold color.
That makes sense.

24. Pyrite or “Fool’s Gold”
When pyrite is run across a streak plate, it has a black or dark green streak.
Pyrite is not worth much money, while gold is worth a lot. They look alike, so miners call it fool’s gold.

25. Hematite Hematite’s color is grey, but its streak is red.
Hema means blood.
The mineral was named hematite because it looked like it was bleeding when it was taken across a streak plate.

26. One mineral property we will not use…
COLOR

27. A mineral can be many different colors. Below is Mica.

28. Many minerals can be the same color. Below are gold colored minerals
Many minerals can be the same color. Below are gold colored minerals. Which one is gold?

29. None of them were real gold.
The answer…
None of them were real gold.