1. Mineral Identification
Using Properties
To Tell Them Apart

2. Each mineral has its own properties that can be used to identify it.
Hardness
Color
Streak
Luster
Density
Cleavage and Fracture
Chemical activity
Special properties

3. Properties Hardness Color
Minerals can scratch any mineral softer then itself and can only be scratched by that of a mineral harder than it.
Moh’s scale of hardness ranks minerals from 1 to 10 in order of increasing hardness.
Color
Can only be used to identify those minerals that have their own characteristic color.

4. Properties Streak Luster
Created when a mineral is rubbed against a hard rough tile that causes it to leave a powder behind
Different minerals leave different color streaks
The color of the mineral does not always match its streak
Luster
Term used to describe how a mineral reflects light from its surface
Terms to describe luster are glassy, earthy, waxy and pearly, metalic

5. Properties Density Crystal shape
Density is the mass of a sample divided by its volume.
In mineral identification density is also called specific gravity.
Crystal shape
Crystals grow atom by atom.
There are six crystal shapes.

6. Properties Cleavage and Fracture
Cleavage is when a mineral splits along flat surfaces.
Fracture is when the mineral does not split evenly but forms a rough surface.
Tell the students that we will not be breaking any minerals to observe cleave.
It is sometime difficult to tell the difference between crystal shape and cleavage unless you break the sample yourself. In some cases the crystal shapes and the cleavage are identical. Halite is one example. You can allow students to look at salt under a microscope to see that it has the same shape as the large halite sample in our set.
Quartz on the other hand grows in beautiful crystal shapes.

7. Quartz
Crystal
Cleavage

8. Halite
Crystal Shape
Cleavage shape

9. Properties Chemical activity
Some minerals react to acid. Mostly the carbonate minerals.
Tell the students that we will not be breaking any minerals to observe cleave.
It is sometime difficult to tell the difference between crystal shape and cleavage unless you break the sample yourself. In some cases the crystal shapes and the cleavage are identical. Halite is one example. You can allow students to look at salt under a microscope to see that it has the same shape as the large halite sample in our set.
Quartz on the other hand grows in beautiful crystal shapes.

10. Reacting to Acid

11. Properties Special properties
Some minerals glow under ultraviolet light
Some minerals give off radiation
Some minerals even have electric properties
A few minerals are attracted to magnets

12. Under Natural Light

13. Under UV light