1. Descriptive Mineralogy
Halides:
Minerals with Halogen Anions

2. Classification of the Minerals
Non-Silicates
Native Elements
Halides
Sulfides
Oxides
Hydroxides
Carbonates
Sulfates
Phosphates
Silicates
Orthosilicates
Sorosilicates
Cyclosilicates
Chain Silicates
Layer Silicates
Tektosilicates

3. Halides: Minerals with halogen anions
Halite (NaCl) and Sylvite (KCl): Evaporites
Fluorite (CaF2) Low temperature hydrothermal
Cryolite (Na3AlF6): Pegmatite

4. Halite Cube

5. Halite NaCl Crystal System Cubic Point Group 4/m-32/m Space Group Fd3m
Optical isotropic 1.51
Color colorless
Luster Vitreous
Hardness 2
Density 2.1 g/cm3

6. Halite NaCl Occurrence: Evaporites, Salt Domes
Uses: Table salt, De-icing, Nuclear waste host rock?

7. Halite has low density and deforms plastically

8. Sylvite KCl Crystal System Cubic Point Group 4/m-32/m Space Group Fm3m
Optical isotropic 1.45
Color colorless
Luster Vitreous
Hardness 2
Density g/cm3
Occurrence EVP

9. Potash Ponds near Moab

10. Fluorite CaF2 Crystal System Cubic Point Group 4/m-32/m
Space Group Fm3m
Optical isotropic 1.43
Color violet, green
Luster Vitreous
Hardness 4
Density g/cm3
Occurrence LTH

11. Fluorite Veins in Granite