1. Chapter 3 Section 1: Properties of minerals
Key concepts:
Mohs hardness scale
Cleavage
What is a mineral?
How are minerals identified?
Fracture
Key terms:
Mineral
Inorganic
Crystal
Streak
Luster

2. What is a mineral?
A mineral is a naturally occurring, inorganic solid that has a crystal structure and a definite chemical composition.

3. Wait, what?

4. 5 parts necessary to minerals
1. Naturally occurring
Not made by people
2. Inorganic
Wasn’t from a living thing
3. Solid
Definite volume and shape, i.e. not liquid or gas
4. Crystal structure
Repeating pattern of particles (crystal)
5. Definite chemical composition
Always contains the same elements in definite proportions

5. Identifying minerals
Each mineral has characteristic properties that can be used to identify it.
Color
Streak
The streak of a mineral is the color of its powder. It can be observed by rubbing the mineral against another surface.
Luster
Describes how light is reflected from a mineral’s surface

6. Density Hardness Each mineral has a characteristic density
Density = mass/volume
Hardness
Ranks 10 materials from softest to hardest
Determined by a scratch test
A mineral can scratch any mineral that is softer than itself

7. Crystal systems
The crystals of each mineral grow atom by atom to form that mineral’s crystal structure

8. Cleavage and fracture
Cleavage: a mineral that breaks easily along flat surface has the property called cleavage. Whether a mineral has cleavage depends on how the atoms in its crystals are arranged.
Fracture: describes how a mineral looks when it breaks apart in an irregular way.
Examples: when quartz breaks, it produces curved, shell-like surfaces that look like chipped glass

9. Special properties
Some minerals can be identified by special physical properties.
For example: magnetism occurs naturally in a few minerals.
For example: minerals that glow under ultraviolet light have a property known as fluorescence.

10. Review questions… What is a mineral?
What are the 5 parts necessary to minerals?
What does fracture refer to with minerals?