1. The substances that make up rocks and Earth’s surface
Minerals
The substances that make up rocks and Earth’s surface

2. MINERALS MINERALS: TWO CATEGORIES
SILICATES – CONTAIN SILICON & OXYGEN MOLECULES (SiO)
NON-SILICATES (NO SiO)

3. NON-SILICATE MINERALS
Make up 5% of Earth’s crust
Native metals: gold, silver, copper
Carbonates: calcite (used in cement)
Oxides: hematite (iron ores)
Sulfides: galena (lead ores)
Sulfates: gypsum (used in plaster)

4. SILICATE MINERALS Make up 90-95% of the Earth’s Crust
Dominant component of most rocks, include:
QUARTZ (SiO2)
FELDSPARS
MICAS

5. Minerals to know Quartz Second MOST ABUNDANT MINERAL IN EARTH”S CRUST
Six-sided crystal shape
Hardness of 7
Many different colors

6. Feldspar MOST ABUNDANT MINERAL IN EARTH”S CRUST
2-directions of cleavage

7. Quartz
Aka: Amethyst, Rose Quartz, Smoky Quartz, etc.

8. Calcite Slanted cubic (rhombic) crystal shape and cleavage
Double refraction
Reacts with acid

9. Halite (rock salt)
Cubic crystal shape and cleavage
Tastes salty

10. Mica 1-direction of cleavage (sheets) Light colored = muscovite
Dark colored = biotite

11. Hematite Can vary greatly Gray or brown-red Brown-red streak
Metallic and non-metallic

12. Pyrite (Fool’s Gold) Golden color Gray-black streak
Cubic crystal shape and cleavage

13. Graphite
1-direction of cleavage
Very soft
Used in pencil lead

14. Talc
Softest mineral (hardness = 1)
Soapy feeling
Many colors

15. Sulfur
Bright yellow or red
Brittle
Smells like rotten eggs

16. Diamond Hardest mineral (hardness = 10) Eight-sided crystal
Many colors

17. Galena Cubic crystals and cleavage Bluish-silver metal
Very heavy (contains lead)

18. ANY QUESTIONS?