1. Earth’s Materials

2. Minerals
On the periodic table, of the first 92 elements: 90 are found in the Earth
The crust is the outermost layer of Earth, and includes all continental material and materials that form the ocean bottom.
Extends 10km beneath the continents

3. Major Elements in the Earth’s crust
Percent ( by mass)
Oxygen
46.6%
Silicon
27.7%
Aluminum
8.1%
Iron
5.0%
Calcium
3.6%
Sodium
2.8%
Potassium
2.6%
Magnesium
2.1%
All others
1.5%

4. What’s a mineral?
A mineral is a naturally occurring element of compound that is inorganic, solid, and has a crystalline structure
Inorganic means that minerals are materials that are not produced by living organisms
The composition of minerals are indicated by their chemical formula
Example: Fluorite= CaF2

5. Physical Properties
A mineral has a particular chemical composition, although can sometimes vary due to small impurities
Example: Ruby vs. Sapphire

6. Example Ruby vs. Sapphire
Both contain corundum, but Ruby has more chromium then Sapphire

7. Atom Arrangement
Some properties are controlled by orderly arrangement of atoms in a mineral’s structure
This pattern is what makes a mineral crystalline
The arrangement of atoms and the bonds between them can reflect the way a mineral breaks, how hard it is, and what type of crystal shape

8. How minerals break
Cleavage: the ability of a mineral break along plans that cut across relatively weak chemical bonds, a smooth, flat surface.
Fracture: an irregular break

9. Hardness
Bonds connecting atoms in materials often have different strengths
When your scratch a mineral with another mineral the scratch forms as bonds in the material are broken.

10. Mohs Scale of Hardness Most to Least Talc Gypsum Calcite Fluorite
Apatite
Feldspar
Quartz
Topaz
Corundum
Diamond

11. Luster and Streak The way a mineral reflects light is known as luster
Metallic
Nonmetallic
The color of a mineral in powdered form is called streak
The streak may be the same color as the mineral