1. Types of Minerals

2. Silicates: The Most Abundant Matter in Earth’s Crust
Minerals that contain silicon and oxygen
Make up ~96% of minerals in the crust
Building block of all silicates = silica tetrahedron

3. Silicates
The silica tetrahedron may arrange itself in many different ways
Structures include:
Quartz and Glass
Aluminosilicates
Individual silicate units
Silicate Chains
Silicate Sheets

4. Silicates: Quartz and Glass
Individual units are SiO4
SiO44- is unstable and covalently bonds with another SiO44- to produce SiO2 (silica)
Examples:
Quartz (organized)
Glass (disorganized / amorphous): silica heated to over 1500ᵒC then cooled quickly.

7. Silicates: Aluminosilicates
Similar to quartz, but aluminum substitutes for silicon atoms.
Instead of SiO2, the functional unit is AlO2-
The charge is balanced by another positive ion from other sources like sodium.

8. Albite: NaAlSi3O8

9. Anorthite: CaAl2Si2O8

10. Silicates: Individual Silicate Units
Sometimes SiO44- bonds with other cations to form orthosilicates
Example: (Zn2SiO4)

11. Silicates: Single Silicate Chains
If the SiO44- units link into long chains through sharing oxygen atoms the structure is called pyroxene. The excess charge is neutralized
by metal cations.
 Augite: (Ca,Na)(Mg,Fe,Al,Ti)(Si,Al)2O6

12. Silicates: Double Silicate Chains
Two silicate chains bonded next to each other are called amphiboles.
Results in fibrous material
 Asbestos:

13. Silicates: Silicate Sheets
When 3 oxygens in a silicate tetrahedron are shared, the result is a sheet called a phyllosilicate.
Metal ions bond between the sheets.
 Mica

14. Carbonates One or more metallic elements and a carbonate ion (CO32-)
 Malachite: Cu2CO3(OH)2

15.  Calcite

16.  Dolomite

17. Oxides A metal bonded to oxygen. Examples: Hematite: Fe2O3
Uraninite: UO2
Magnetite: Fe3O4

18. Your Turn
Use pp to describe the different between minerals, ores and gems.